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1 Grammatical Aspects of Specific Language Impairment: A Linguistic Perspective Andrew Radford, University of Essex, 17 March 20061 Contents Page Preface 2 1. Introduction to SLI 3 2. The Perceptual Deficit account of SLI 12 3. The Feature Blindness account of SLI 18 4. The Rule Deficit account of SLI 24 5. The Agreement Deficit account of SLI 31 6. The Agreement-and-Tense-Omission (ATOM) account of SLI 38 7. The Dependency Deficit account of SLI 51 8. Empirical Study I: The acquisition of past tense marking 60 9. Empirical Study II: The acquisition of s-forms 75 10. Empirical Study III: The acquisition of inflected main-verb forms 92 11. Empirical Study IV: The acquisition of subject case-marking 100 12. References 108 13. Appendix: Transcripts from a 4-year-old American boy with SLI 111 1 This coursebook should be cited in references in the following form: Radford, A (2006) Grammatical Aspects of Specific Language Impairment: A Linguistic Perspective, unpublished coursebook, University of Essex (http://courses.essex.ac.uk/lg505) 2 Preface Overview This book provides a linguistic perspective on the grammatical development of children with a language disorder known as Specific Language Impairment/SLI. It is intended for intermediate or upper undergraduates and beginning graduates. It presupposes no previous knowledge of SLI, and assumes only the kind of background knowledge of traditional linguistic concepts (such as e.g. morpheme) which students acquire from an introductory Linguistics textbook such as Radford et al. (1999). It is written in an approachable style, avoiding unnecessary jargon and theoretical sophistication (or sophistry), with copious footnotes designed to answer the kinds of questions which beginning students ask. The main focus throughout is on English-speaking children with SLI. Key features There are three key features of the book which merit comment. The first is that (in recognition of the fact that students have increasing demands on their time these days and so have less and less time to devote to preparing for courses), I have kept the book short, so that you should be involved in doing not more than an hour or two of preparatory reading for each of the core chapters. I have also built each core chapter round a single key article – because past experience of asking students to read several articles before a class is that virtually none of them manage to read all of the articles, and most read no more than one (and yes, you’ve guessed it, each student reads a different article!). A second key feature of the book is that it is designed to be interactive. Each of the core chapters contains a brief summary (generally around 5 pages or so in length) of the relevant key article, followed by a workbook section containing several pages of questions and exercises. The questions are designed to get you to demonstrate that you have understood key points in the article, and to think critically and independently about the relevant research. The exercise material is designed to get you to analyse small sets of data and show how they can be used to test particular claims made by a particular theory. The overall aim of the workbook section is to foster an interactive teaching style in the classroom. A third key feature of the book is that it contains a substantial empirical component designed to get you to undertake a small-scale piece of original research for yourself on a number of alternative topics. Detailed step-by-step guidance is provided on how to undertake the research, and how to write it up. Organisation The book begins with an overview of SLI, followed by 6 core chapters outlining key theories of SLI, with each chapter including several pages of material for class discussion. The remaining four chapters provide step-by-step guidance on how to conduct a small-scale piece of empirical research into the nature of SLI on your own, using a set of transcripts of the language production of a four-year-old boy with SLI which you are provided with (in the Appendix). 3 1. Introduction to SLI The Nature of SLI Specific Language Impairment (conventionally abbreviated to SLI, and also referred to as developmental dysphasia) is a developmental language disorder characterised by Gleason (2001, p. 504) as involving ‘delayed or deviant language development in a child who exhibits no cognitive, neurological or social impairment’. Children with SLI show impaired language development from birth (with problems which may either disappear during childhood or persist into adulthood) but are normal in other aspects of their physical, mental and social development, and so have: (1) • a score within the normal range on non-verbal intelligence tests2 • normal hearing3, and no recent ear infections • no oral abnormalities4 • no neurological dysfunctions5 (e.g. brain lesions, brain injury, cerebral palsy, seizures) • no behavioural, emotional, communicative or social problems (e.g. no autism) See Bishop (1997), Leonard (1998), and the collection of papers in Bishop and Leonard (2000) and Levy and Schaeffer (2003) for more detailed discussion of diagnostic criteria for SLI. Prevalence and Persistence of SLI Leonard (1989) estimates that around 6% of children suffer some form of language impairment (with 1.5% having a tested language age of less than two thirds of their tested mental age), and that SLI affects around 3 times more males than females. Some SLI children6 seem to grow out of SLI during childhood, while for others the symptoms persist into adulthood. Bishop & Edmundson (1987) report that of 68 children diagnosed as suffering from SLI at 4 years of age, 56% continued to show poor scores in language tests at ages 5;6 and 8;6; Johnson et al (1999) report that 73% of the preschool children they tested who were language-impaired continued to be language-impaired at age 19. However, van der Lely and Battell (2003) suggest that children who ‘grow out of’ SLI may not be suffering from SLI at all, but rather may simply be late developers’ (i.e. children who develop in the same way as normal children, but more slowly). The issue amounts to whether SLI is seen as a disorder which makes it impossible for children to acquire certain aspects of language, or as a disorder which makes them very slow at acquiring the relevant aspects of language. Comparing SLI children with TD (= typically developing) children In order to determine the extent to which the language of SLI children is impaired, we need to compare them with typically developing (= TD) children. However, this raises the question of what kind of TD children we compare SLI children with. There are three main groups of TD children which SLI children are typically compared with, namely: (2) • chronological age controls (i.e. TD children of the same chronological age) • mental age controls (i.e. TD children who have comparable scores on non-verbal intelligence tests) • language age controls (i.e. TD children with comparable scores on tests of vocabulary or grammar) Studies of SLI children’s grammatical development usually compare SLI children with TD children at the same stage of grammatical development. A conventional way of quantifying a child’s grammatical development is in terms of Mean Length of Utterance (conventionally abbreviated to MLU). A child’s MLU is calculated by taking a sample of (say) 50 or 100 spontaneous speech utterances produced by the E.g. a score of 85 or above on Arthur’s (1952) adaptation of the Leiter International Performance Scale or on the British Ability Scales (Elliott et al. 1978). 3 Determined by a pure tone screening test. 4 As determined by a screening procedure like that in St. Louis and Ruscello (1981) 5 Determined by passing a screening test for neurological function such as that in Tallal, Curtiss and Kaplan (1980). 6 I shall use the term SLI children throughout – though you might note that some regard this term as ‘politically incorrect’ and prefer the term children with SLI. 2 4 child, and calculating the mean number of morphemes7 per utterance in the child’s speech sample (by adding up the total number of morphemes which the child produces and dividing it by the number of utterances the child produces): see Brown (1973) and Miller et al. (1981) for procedures for computing MLU. So, for example, if we were studying a group of 5-year old SLI children, we might compare them both with 5-year old TD children (= chronological age controls), and with TD children who have comparable MLU scores (= MLU controls). This would in effect mean that we’d compare 5-year old SLI children with 3-year-old TD children, since 5-year old SLI children generally have much the same MLU as 3-year-old TD children. Differences between SLI and TD children If we compare SLI children with typically developing age controls we find: (3) • SLI children have scores significantly below TD children on language tests (e.g. SLI children’s MLU is only around two thirds that of TD children, so that a 3-year old SLI child will have the language age of a 2-year old TD child, and a 5-year old SLI child will have the language age of a 3-year-old) • TD children produce their first word around 11 months of age, SLI children around 23 months • TD children produce their first multiword combinations (e.g. Want chocolate) around 17 months, SLI children around 37 months. • SLI children show a higher proportion of errors then TD children Overall characteristics of SLI SLI children typically show some (or all) of the following types of impairment: (4) • phonological (e.g. problems with consonant clusters and syllable-final consonants) • grammatical (e.g. sporadic omission of affixes/inflections and articles/particles) • lexical (delayed acquisition of words – e.g. first word appears around 23 months in SLI children, but around 11 months in TD children; SLI children also have word-finding problems) • comprehension problems (e.g. problems with understanding metaphors) • reading problems Note, however, that SLI children differ in the extent to which their comprehension and/or production abilities are impaired: for more details, see the literature survey in Leonard (1998) chapter 3. Van der Lely (2003) notes that SLI in some children is primarily characterised by a grammatical deficit, and refers to the relevant type of SLI as GSLI. In this book, I focus on grammatical errors made by SLI children, concentrating mainly on those around 4-5 years of age. Overview of the grammatical errors made by SLI children SLI children are traditionally said to make two main kinds of grammatical error, namely: (5) • omission errors (sometimes omitting an item8 which would be obligatory in the adult grammar) • commission errors (sometimes using an item in an inappropriate form or position). For example, in a context where an adult would use a sentence like Where’ve they gone?, SLI children around 4-5 years of age will sometimes produce the correct adult form, sometimes produce a sentence like (6a) below, sometimes a sentence like (6b), and sometimes a sentence like (6c): (6)(a) 7 Where they gone? (b) Where’s them gone? (c) Where they’ve gone? Morphemes are grammatical units: e.g. an item like cats is a single word but two morphemes, comprising the noun stem cat and the plural suffix -s. Although MLU is generally computed in terms of the mean (i.e. average) number of morphemes per utterance for languages like English in which many words carry no overt inflections, for languages like Italian or Spanish in which all words typically consist of a stem plus an affix or inflection, MLU is generally computed simply in terms of words. When this is done, the abbreviation MLU(W) – i.e. mean length of utterance measured in terms of words – is often used, for the sake of clarity. 8 The term item here is used informally to subsume both independent words and inflections/affixes/clitics. 5 (6a) involves an omission error, namely omitting the auxiliary HAVE. (6b) involves two commission errors, one being the use of the wrong form of HAVE – using the third person singular form (ha)s instead of the third person plural form (ha)ve – and the other being the use of the wrong form of the subject pronoun (using the accusative form them in place of the nominative form they). (6c) involves a different kind of commission error, namely placing the auxiliary HAVE after the subject they instead of before it (i.e. failing to invert the auxiliary with the subject and so failing to position the auxiliary in front of the subject, yielding the word order they have instead of the required adult order have they). In the various sections below, I give a (superficial) classification of typical grammatical errors made by SLI children. Unless otherwise stated, the illustrative data come from the Leonard files on the CHILDES data base (MacWhinney 1993; http://childes.psy.cmu.edu). These are transcripts of spontaneous speech samples from eleven SLI children aged between 3;8 and 5;7 collected by Larry Leonard; the children are identified in the files only by letters (as child A, child B, child C, child D etc.). Accordingly, a letter like [D] in square brackets after a particular example below indicates that the example was produced by child D. Omission of affixes A frequent type of grammatical error made by SLI children is omission of affixes. The term affix is used to describe a grammatical morpheme which cannot stand on its own as an independent word, but which must be attached to a host of an appropriate kind (i.e. to a suitable kind of word or expression). Affixes found in English include: (7) • genitive ’s9 on noun expressions like the president’s (as in The president’s car is bomb-proof) • plural -s on nouns like cars (as in two cars) • present-tense -s on verbs like knows (as in He knows her well) • past-tense -d on verbs like lied (as in The president lied to Congress) • progressive/gerund -ing on verbs10 (as in He was nodding off while listening to the talk). Omission of an affix typically results in the production of a bare form (i.e. the production of an uninflected word form which comprises a stem without any overt inflection). Illustrative examples of affix-omission errors produced by SLI children (from the Leonard corpus) are given in the table below: (8) Affix-omission made errors by children with SLI Illustrative example You know what my doctor name is? (= ‘my doctor’s name’) Then I wanna put more sticker on (= ‘more stickers’) My dad drink tea (= ‘My dad drinks tea’) I drop him (= ‘I dropped him’) We were do Superman (= ‘We were doing Superman’) child E J E J D Item omitted genitive ’s plural -s present-tense -s past tense -d progressive -ing Omission of auxiliaries Many auxiliaries in English have both a full form and a (contracted) clitic form. The term clitic denotes a reduced form of another word, and has the property that it must cliticise (i.e. attach) to an appropriate kind of word which can serve as its host. In its clitic form, a contracted auxiliary attaches to the word immediately preceding it – as in the examples below: Since children invariably use genitive ’s to mark possession, you can think of this informally as possessive ’s. When used together with the auxiliary BE in sentences like He is sleeping an ing-form marks an action in progress and is said to be a progressive participle in that use. In (most) other uses, ing-forms of verbs are said to be gerunds (e.g. ‘I don’t want him upsetting her’). 9 10 6 (9) Full and clitic auxiliary forms in adult English full form clitic form John is lying/John is lazy11 John’s lying/John’s lazy What does he want? What’s he want? John has gone home John’s gone home They have done it They’ve done it You will regret it You’ll regret it He would like to see you He’d like to see you She had already left She’d already left Who did you see? Who’d you see? In spoken English (i.e. the form of English which constitutes the speech input to young children), clitic forms are generally preferred to full forms wherever possible – though in some contexts a full form is required (e.g. in John’s lying, I know he is we cannot replace the word is at the end of the sentence by its clitic counterpart ’s). However, SLI children frequently omit auxiliaries in contexts where adults would use a clitic form of the auxiliary in colloquial English, as we see from the examples below: (10) Auxiliary-omission made errors by children with SLI Illustrative example child How you get this out? (= ‘How d’you get this out?’) A Where this go? (= ‘Where’s this go?’) A It not wood (= ‘It’s not wood’) D Somebody coming (= ‘Somebody’s coming’) D He got no eyes (= He’s got no eyes’) A I been there (= ‘I’ve been there’) D Yeah, that be fun (= ‘Yeah, that’ll be fun’) D Item omitted auxiliary d(o) auxiliary (doe)s copula (i)s auxiliary (i)s auxiliary (ha)s auxiliary (ha)ve auxiliary (wi)ll Omission of pronouns As well as omitting auxiliaries, SLI children also sometimes omit pronouns – more specifically, weak pronouns (i.e. those which are unstressed and non-contrastive in use) like I/we/you/he/she/it/they. Such weak pronouns often have a reduced form: for instance, he can be reduced to ’e in colloquial English, in a sentence such as (H)e’s lying, I know (h)e is. Examples of pronoun-omission by children with SLI are given in the table below; as some of the examples show, children may sometimes omit both a subject pronoun and an auxiliary in the same clause (usually when one cliticises to the other in adult English, e.g. as in d’you = do you): (11) Omission of subject pronouns by children with SLI Illustrative example child Item(s) omitted But can fit? (= ‘But can it fit?’) A subject pronoun it Need no more (= ‘I need no more’) B subject pronoun I How do skate?12 (= How does it skate?’) B subject pronoun it If you chew on it, break (= ‘…it’ll break’) A it’ll (subject pronoun it and auxiliary will) Got small knees (= ‘He’s got small knees’) A He’s (subject pronoun he and auxiliary has) How pull this off? (= ‘How d’you pull this off?’) A d’you (auxiliary do and subject pronoun you) 11 In structures like John is lazy, John is in Paris and John is a doctor, the word BE is traditionally said to be a copula (a Latin word meaning ‘link’) in that it serves to provide the sentence with a verb which links the subject John with the non-verbal (predicative) expression following it – i.e. lazy/in Paris/a doctor. However, even in this copular use, BE also functions as an auxiliary, and so (e.g.) undergoes inversion in questions like Is John lazy? 12 The child immediately afterwards asks ‘How do it skate?’ (omitting the -es inflection on do). 7 Omissions of articles and particles A further characteristic of the speech production of SLI children is omission of articles and particles13. The word the is termed a definite article in traditional grammars, and the word a(n) is traditionally classified as an indefinite article. Articles are frequently omitted by SLI children in obligatory contexts (i.e. in contexts where it would be obligatory for an adult speaker to use an article). Once such obligatory context for the use of articles is with expressions containing a singular count noun14. For example, We can’t say *Can I borrow computer? in English because computer is a singular count noun, and singular count nouns require an article (or similar kind of word) in front of them (as we see from the fact that we say Can I borrow a/the computer?). The word to when followed by a verb in its (bare/uninflected) infinitive form is traditionally termed an infinitive particle: so, in I want to go home, to is an infinitive particle and go is an infinitive verb form. SLI children sometimes omit infinitival to in obligatory contexts (i.e. in contexts where adults require it) A second kind of grammatical particle is the genitive case particle of. In expressions like the cover of the book, the word of is traditionally said to be a Norman genitive case particle (because it corresponds to French de ‘of’) – whereas the ’s affix in the book’s cover is said to be an Anglo-Saxon case particle. SLI children frequently omit genitive particles. (I return to consider case errors below.) A third type of grammatical particle are clause-introducing particles (in more recent work, termed complementisers) like that/for/if in sentences like ‘He said that he was tired’, ‘She’s keen for him to be there’, and ‘I doubt if he will come’. SLI children sometimes omit such particles in obligatory contexts15. Examples of article and particle omission by SLI children are given below: (12) Omission of articles and particles by children with SLI Illustrative example child Can I finish game? (= ‘the game’) A Sue wanna take bath (= ‘a bath’) C Julie wanted eat his breakfast (= ‘to eat’) C What kind books? (= ‘What kind of books?’) G Time me to get another one? (= ‘Time for me to…’) A Item omitted definite article the indefinite article a infinitive particle to genitive case-particle of clause-introducing particle for Explaining omission errors Why should it be that SLI children frequently omit affixes, clitics, articles and particles? There are two opposing schools of thought relating to this question. One view known as the Perceptual Deficit Hypothesis (and articulated by Leonard 1989) is that the items concerned are omitted because they are difficult for SLI children to perceive because of their lack of phonetic substance. The perceptual difficulties stem from the fact that the omitted items are typically unstressed, comprise only one or two (consonant or vowel) segments, and often contain a short, weak schwa vowel (as in the articles the and a, and particles like infinitival to and genitive of) or have no vowel at all (as in the clitic form of have found in They’ve gone home). A diametrically opposed Grammatical Deficit view (articulated in an early form by Gopnik 1990, and in more recent forms by Clahsen Bartke and Göllner 1997 and by Wexler, Schütze and Rice 1998) is that children have problems in processing grammatical features and so (perhaps in order to reduce their grammatical processing load) sometimes omit some of them. We can illustrate the difference in the two approaches by the following set of examples. Suppose that an SLI child omits plural -s in an expression like two car. The perceptual deficit account claims that plural -s poses perceptual problems because it comprises only the consonant segment |z|. The The term particle is used to denote a ‘short’ word which does not easily fit into conventional systems of grammatical categories/parts of speech (e.g. isn’t a typical noun, verb, adjective, adverb, preposition etc.) 14 A count noun is a noun like chair which can be counted (in that we can say one chair, two chairs etc.). By contrast, a noun like furniture which cannot be counted (cf. *one furniture, *two furnitures etc.) is called a non-count noun or mass noun. 15 An obvious complication is posed by the fact that the particle/complementiser that can frequently be omitted in adult English, so that alongside ‘He said that he was tired’ we can also say ‘He said he was tired’. 13 8 grammatical deficit account posits that omission of the plural -s ending stems from the fact that the child omits the plural-number feature on the noun car (perhaps to reduce the feature-processing burden). Now suppose that an SLI child omits past tense -d in ‘Daddy play with me yesterday’. The perceptual deficit account claims that past -d poses perceptual problems because it comprises only the consonant segment |d|. The grammatical deficit account posits that omission of the past-tense -d ending occurs because the child does not specify the verb for past tense (i.e. omits the past tense feature on the verb). Finally, suppose that a child omits the present-tense auxiliary ’s in a sentence like Daddy’s working and so says simply Daddy working. The perceptual deficit account says that this is attributable to perceptual problems caused by the fact that ’s is a clitic with little phonetic substance, comprising only the consonant segment |z|. The grammatical deficit account (by contrast) says that children omit items which are lack one or more of the grammatical features which they would carry in adult English: so (for example), if the child fails to mark the auxiliary for tense, the auxiliary will be omitted16. Commission errors: inflections In addition to omission errors, SLI children frequently made commission errors. The commonest pattern of commission error we find involves producing over-regularised forms of irregular words. For example, the noun mouse in English has the irregular plural form mice: but SLI children sometimes add the regular plural affix -s to the stem mouse and so produce the over-regularised form mouses. Similarly, in place of the irregular past tense form bought SLI children sometimes use an over-regularised form like buyed (formed by adding the regular past tense ending -ed to the stem buy). Indeed, sometimes we find multiply inflected forms in which the regular past tense ending is attached to an adult irregular past tense form, resulting in forms like wented (with regular -ed attached to the irregular past form went). In addition, in structures in which a (present or past) tensed auxiliary or verb is followed by an infinitive form, SLI children will sometimes use a tensed form in place of the infinitive (resulting in a tense-copying structure containing two tensed verbs, e.g. He didn’t played with me instead of He didn’t play with me). Examples of these errors are given below: (13) Commission errors with inflections made by children with SLI Illustrative example child Nature of error Firemans live over here (= ‘Firemen’) G over-regularised noun plural form Something hurted you (= ‘hurt you’) E over-regularised past tense form This broked (= ‘This broke’) E multiply inflected past form (past broke + past -ed) It doesn’t really closes A tense-copying from does onto closes Case-marking errors A further type of commission error made by SLI children are case errors. Personal pronouns in English have a number of distinct case forms. For example, the third person singular masculine personal pronoun in English has three different forms – namely, the nominative form he, the genitive form his, and the accusative (or objective) form him. Some personal pronouns have separate weak (= short) and strong (= long) genitive forms. A weak genitive form like my is used when the genitive pronoun modifies an immediately following noun expression of some kind, as an my new car (where genitive my modifies the noun expression new car); a strong genitive form like mine is used when the genitive does not modify an immediately following noun expression (as in This is mine or Mine is bigger than yours). The case carried by a pronoun determines the spellout (i.e. superficial form) of the pronoun, as the table below illustrates: This could be argued to be because although a child’s lexicon (i.e. mental dictionary) tells the child (e.g.) that BE is spelled out as (i)s if it carries the features ‘third person singular present tense’, it provides the child with no way of spelling out a tenseless form of BE which simply carries the features ‘third person singular’. Of course, BE would also be omitted if it was not marked for agreement with the subject and so had no person and/or number features. 16 9 (14) Case Spellout Table: How case is spelled out on personal pronouns in adult English Pronoun Spellout 1.SG I if nominative, mine if a strong genitive, my if a weak genitive, me otherwise 1.PL we if nominative, ours if a strong genitive, our if a weak genitive, us otherwise 2.SG/PL yours if a strong genitive, your if a weak genitive, you otherwise 3.M.SG he if nominative, his if genitive, him otherwise 3.F.SG she if nominative, hers if a strong genitive, her otherwise 3.N.SG its if genitive, it otherwise 3.PL they if nominative, theirs if a strong genitive, their if a weak genitive, them otherwise NB: 1/2/3 denote 1st/2nd/3rd person; SG = singular; PL = plural; M = masculine; F = feminine; N = neuter The otherwise form of the pronoun is termed its default form (the idea being that this is the form used by default if the conditions for using other forms are not met). Studies of SLI children report that they make case errors with personal pronouns: however, these case errors are not random, but rather show a systematic pattern. The pattern we typically find is that SLI children alternate between the correct adult forms and default forms. So, in a nominative context (i.e. a structure in which adults would use a nominative pronoun like I/we/he/they etc.) SLI children will typically alternate between correctly using the nominative form of the pronoun (so saying e.g. I want one) and incorrectly using the default form (so saying e.g. Me want one). Likewise, in a genitive context (i.e. a context in which adults produce a structure like his car where the genitive pronoun his marks possession) SLI children will usually alternate between correctly producing the genitive form (saying his car) and incorrectly producing the default form (saying him car). A further type of case error which SLI children make is to confuse the two genitive forms – e.g. using a strong form like mine where an adult would use a weak form like my (or conversely) – e.g. saying Mine car or This is my. As we noted earlier, SLI children sometimes also omit the genitive case affix ’s in obligatory contexts, and so alternate between saying Daddy’s car and Daddy car. If we assume that noun expressions have the suffix ’s added to them when genitive in case but are otherwise bare (i.e. uninflected), then we could see the use of a bare possessor like Daddy as being an instance of the use of a default form (= Daddy) in a context where adults require the genitive form Daddy’s. If so, omission of genitive ’s would be a grammatical error (use of a default form in place of a genitive form) rather than a perceptual error (omission of a morpheme because of perceptual problems posed by its lack of phonetic substance). Typical examples of case errors made by SLI children are given below: (15) Case errors made by children with SLI Illustrative example child Me don’t want those D Him eyes have water in D Mine baby fits B You know what my doctor name is? E Nature of error use of default form me for nominative I use of default form him for genitive his use of strong genitive mine for weak genitive my omission of genitive ’s Commission errors: word order A further type of commission error made by SLI children are word-order errors. The main type of word error made by English SLI children involves failure to invert subject and auxiliary in (main-clause) questions – as illustrated earlier by example (6c) Where they’ve gone? Rather more rare is the converse error of incorrectly inverting an auxiliary with its subject in a complement-clause question. Examples of both types of auxiliary inversion error are given below: (16) Auxiliary inversion errors made by children with SLI Illustrative example child Nature of error Which one I can do? C failing to invert can with I Where this is? C failing to invert is with this Know what one is it? A inverting is with it in a complement clause 10 Nature of commission errors What’s the nature of the commission errors made by SLI children? It’s hard to see how errors which involve using an inappropriate form of an item (e.g. using the default form them in place of the adult genitive form their to mark the possessor in them house) could be the result of a perceptual deficit, since the adult genitive form their should not pose perceptual problems (and would seem to have more or less the same amount of phonetic substance as the default form them). Nor is it obvious how word order errors like failure to apply auxiliary inversion could be the result of a perceptual deficit, since the problem is not that the child doesn’t perceive the auxiliary and omits it, but rather that the child uses the auxiliary, but fails to move it in front of the subject in a main clause, or (conversely) wrongly moves it in front of the subject in a complement clause. It would seem more likely, then, that commission errors reflect a grammatical (rather than a perceptual) deficit. Overall nature of SLI An important debate in the SLI literature revolves round the question of whether SLI is the result of delayed development (with SLI children going through the same stages as TD children but more slowly, and sometimes reaching a plateau – i.e. a stage beyond which they never progress), or deviant development (with SLI children showing abnormal patterns of development not seen in TD children): this can be succinctly referred to as the delay/deviance debate. A second debate relates to whether SLI is a homogeneous disorder (in which all affected children show the same forms of language impairment) or a heterogeneous disorder (in which different children show different forms of language impairment). A related question is whether SLI represents a global impairment of grammar (with all aspects of grammar being affected) or a selective impairment (with only some aspects of grammar being affected). Yet a further controversy surrounds the question of whether SLI children show evidence of other primary (e.g. cognitive) impairments or not: see Leonard (1998, chapter 5) for a summary of research arguing that SLI children may show a cognitive deficit, and are less good at pretend play and mental imagery (e.g. imagining objects in different orientations) than typically developing (= TD) children. Genetic basis of SLI A fair amount of evidence has been accumulated in support of the view that SLI is a genetically transmitted disorder. Family studies show that between a quarter and two-thirds of immediate family members (siblings and parents) of children with SLI have language problems (e.g. Gopnik and Crago 1991 report that around half the members of a 3-generation family they studied were affected by SLI; and Rice, Wexler and Hanney 1998 report that the incidence of language disorders in families which have a child with SLI is 22%, compared to only 7% in those which do not). Twin studies show a concordance rate of 80-86% for identical twins (i.e. that in 80-86% of cases where one twin is diagnosed as having SLI, the other has also been diagnosed as having SLI), and a concordance rate of 38-48% for non-identical twins (see Tomblin and Buckwalter 1998 for discussion of the implications of twin studies). The fact that SLI is three times more frequent in boys than girls also suggests a genetic basis for the disorder. Genetic studies have shown that people affected with SLI have an anomaly in chromosome 7, as well as other genetic anomalies (See Fisher et al. 1998, Tomblin et al 1998, Lai etc al. 2001, and a study by the SLI consortium 2002). 11 Workbook section §1.1 Sentences produced by children with SLI Below are a number of sentences produced by the SLI children in the Leonard files on the CHILDES database (the child producing each sentence being identified by a letter: e.g. (B) denotes child B)17: 1 Maybe goes on this one (B) 2 What say? (B) 3 Can get us some them? (C) 4 Do this come out? (C) 5 Billy wanna has his blocks out (C) 6 The tree must broken off (C) 7 Superman have him hands up (D) 8 And they’re jump in water (D) 9 This is mine daddy’s (D) 10 I will be Chad brother (D) 11 Them is boys (D) 12 Me don’t know how do it (D) 13 How you knowed? (E) 14 It cames off (F) 15 I didn’t sawed you come in (G) 16 Think her too growed up (G) 17 What is this is? (H) 18 What next one is? (H) 19 Hope him gonna hit him butt (J) 20 Me no like him (K). Discuss the nature of the errors found in each sentence. The adult equivalents of these sentences are: 1 Maybe it goes on this one. 2 What d’you/did you say? 3 Can you get us some of them? 4 Does this come out? 5 Billy wants to have his blocks out. 6 The tree must have broken off. 7 Superman has his hands up. 8 And they’re jumping in the water. 9 This is my daddy’s. 10 I will be Chad’s brother. 11 They are boys. 12 I don’t know how to do it. 13 How did you know? 14 It came off. 15 I didn’t see you come in. 16 I think she’s too grown up. 17 What is this? 18 What is the next one? 19 I hope he’s gonna hit his butt. 20 I don’t like him. 17 12 2. The Perceptual Deficit account of SLI Key article Leonard LB (1989) ‘Language learnability and specific language impairment in children’, Applied Psycholinguistics 10: 179-202 OUTLINE OF LEONARD’S PERCEPTUAL DEFICIT HYPOTHESIS Larry Leonard (over the past two decades) has developed a particular theory of SLI known as the Perceptual Deficit Hypothesis. He maintains (1989, p.181) that ‘SLI children have notable limitations in the use of certain inflections, auxiliaries and closed-class morphemes18 such as articles’, noting (1989, p.182) that: (1) The most obvious error in the speech of older SLI children is the omission of obligatory grammatical morphemes. The striking feature of this usage is that omissions occur in sentences containing otherwise complex structures such as conjoining, complementation and relativization19. The fact that SLI children can produce complex sentences like (2) below20 suggests to Leonard that the errors they make are not due to processing overload problems caused by complex structures: (2)(a) (b) (c) Then he went home and tell mother – his mother – what he doing that day Then about noontime those guy went in and eat and warm up That boy climbing a rope to get to the top of the rope Further evidence supporting this view comes from the fact that the same omission errors occur in shorter sentences like (3) below (where processing complexity doesn’t come into play): (3)(a) He want play that violin (b) Those men sleeping (c) Can I play with violin? Why SLI is not a grammatical deficit On the basis of data from English children with SLI (= ESLI children) and Italian children with SLI (= ISLI children), Leonard argues that the deficit which affects the language of SLI children is not an intrinsically grammatical one (e.g. an inability to form plurals, or present/past forms etc.). In support of this claim, he adduces a number of arguments, including the following: (4)(i) ESLI children perform relatively well on irregular forms but relatively poorly on regulars (e.g. they perform better on irregular past tense forms like gave than on regular past tense forms like played) (ii) ESLI children perform better on uncontractible copula/auxiliary21 forms than on contractible forms (iii) ISLI children perform better on marking morphological properties (e.g. plural number on nouns, tense/agreement on verbs, concord between nouns and modifiers22) than ESLI children Closed-class items are items belonging to a category with a very small number of members – e.g. auxiliaries, determiners, pronouns etc. They are so-called functors/function words or what Brown (1973) called grammatical morphemes. By articles Leonard means the so-called definite article the and the indefinite article a(n). 19 Conjoined structures are those like Daddy came home and he played with me where two structures are joined together by a co-ordinating conjunction like and/or. A complementation structure is one containing a main clause and a complement clause like Daddy says that we can go to the zoo where the clause [that we can go to the zoo] is the complement of the verb say. A relativisation structure is one containing a relative clause which modifies a noun or pronoun expression: in a sentence like He is someone who I like, the clause who I like is a relative clause in the sense that it ‘relates to’ (i.e. refers back to and modifies) the pronoun someone. 20 The data in (1) and (2) are from a 16-year old child with SLI reported on in a study by Weiner (1974). 21 On the copula/auxiliary distinction, see footnote 19. Contractible forms are forms which can be contracted; uncontractible forms are those which cannot be contracted. For example, in a sentence such as John is lying, I know he is, the first occurrence of BE is contractible to ’s but the second is uncontractible. 22 The term agreement is traditionally used to denote matching the person/number features of an auxiliary/verb to those of its subject; the term concord is used for matching the number features of a noun to those of a modifier (in structures like this book/these books). In Italian, adjectives and determiners undergo number/gender concord with a noun that they modify, as in questa bellissima macchina ‘this beautiful car’, where -a is a feminine singular suffix. 18 13 If the deficit in children with SLI were purely grammatical, Leonard reasons, we should expect them to perform equally poorly on regular and irregular inflected forms, and on contractible and uncontractible forms; likewise, we should expect Italian children with SLI to be just as bad at inflectional morphology as English SLI children. The overall conclusion which Leonard draws from such observations is that SLI is not an intrinsically grammatical deficit. SLI as a perceptual deficit Leonard (1989, p. 188) provides an Auditory Perceptual Deficit account of SLI under which the poor performance of SLI children on certain grammatical morphemes is attributable to a perceptual deficit. The relevant morphemes, he claims, cause perceptual difficulties because of their ‘low phonetic substance’23. Key assumptions made by Leonard are that (because they have more ‘phonetic substance’): (5)(i) (ii) (iii) (iv) Vowels and diphthongs are easier to perceive than consonants (and consonants are particularly difficult to perceive when they occur at the end of syllables/words, or in a consonant cluster24) Stressed vowels are easier to perceive than unstressed vowels Long vowels and diphthongs are easier to perceive than short vowels Full vowels are easier to perceive than reduced vowels25 Leonard, McGregor and Allen (1992) present experimental evidence in support of the claim that vowels are more perceptually salient than consonants. They compared the performance of 8 monolingual SLI children in the age range 4;6 to 5;7 with 8 TD children in the same age range on a perception test using computer-synthesised syllables. They found that SLI children had ‘great difficulty’ in perceiving the contrast between [das] and [da∫] (only 1 of the 8 SLI children passed the test, compared with 5/8 of the TD children), but by contrast had no problems in perceiving the contrast between the vowels [i] and [u]. They conclude from this that there is evidence that consonants (particularly those at the end of a syllable/word) pose more perceptual problems than vowels. More specifically, Leonard claims that ‘SLI children are especially limited in their ability to perceive and hypothesize low phonetic substance morphemes’26. What this implies is that the degree to which a child will have problems in acquiring a particular morpheme will depend on whether it contains a stressed or unstressed, long or short, full or reduced vowel – or no vowel at all. Leonard claims (1989, p.187) that the following morphemes (by virtue of having little phonetic substance) pose problems for ESLI children: (6) 23 past/perfect/passive -d, present tense -s, plural -s, genitive ’s, contracted forms (like the contracted ’s form of is/has, and the contracted ’ll form of will), the definite article the and the indefinite article a, the infinitive particle to, and the complementiser that27 Note that phonetic substance is not a standard term in Phonetics; it is an informal term used by Leonard to indicate the degree of perceptual salience that sounds have (i.e. how easy to perceive they are). 24 A consonant cluster is a set of two or more immediately adjacent consonants – e.g. str is a consonant cluster in the word string. 25 To illustrate the difference: the ‘o’ vowel in the noun content (in a sentence like ‘Your claim has no empirical content’) is a full vowel, whereas the ‘o’ vowel in the adjective content (e.g. in ‘He was feeling very content with life’) is a reduced vowel, pronounced as schwa |ə|. 26 Note that the relevant children do not have a hearing deficit (i.e. they show no signs of deafness). Rather, the deficit lies in their ability to process speech sounds. 27 The suffix -d is a past tense marker in a sentence like They arrested a group of England football fans yesterday, a perfect participle marker when used with the auxiliary have in a sentence like They have just arrested a group of England football fans and a passive participle marker when used with the auxiliary BE in a sentences such as A group of England football fans were arrested. In a sentence such as Dan’s girlfriend likes roses, the suffix ’s on DAN marks genitive case (and serves to indicate what we can loosely term ‘possession’), the suffix -s on the verb LIKE is a thirdperson-singular present-tense marker, and the suffix -s on the noun ROSE is a plural marker. The word that functions as a complementiser (= complement-clause-introducing particle) in sentences like I said that I was tired (but is a demonstrative determiner in That one is mine and a demonstrative pronoun in That is mine). Presumably, Leonard’s reason for including the/a/to/that in his list of low-phonetic-substance morphemes is that they can have their vowel reduced to schwa, as in |ðə, ə, tə, ðət|. 14 In terms of Leonard’s assumptions in (5) and (6), we can account for his observations in (4) as follows: (4i): SLI children will find it easier to produce irregular past tense forms like gave than regular past tense forms like played because the irregular past tense form gave involves marking past tense by the use of a stressed diphthong |eI| in |geIv| which is phonetically substantial (and perceptually salient) by virtue of being unreduced and relatively long, whereas the past tense of play is marked by the addition of the (phonetically insubstantial) word-final consonant |d| in |pleId| (cf. Leonard 1989, p.187). (4ii): Uncontractible forms (like is in ‘Yes it is’) are phonetically more substantial than contracted forms (like ’s in It’s nice) by virtue of containing a vowel. (4iii): In Italian, inflections are typically vocalic in nature (i.e. comprise or contain a vowel/diphthong), whereas in English inflections are typically consonantal in nature. Hence, in an English sentence like Mary sings, the third person singular inflection -s is phonetically insubstantial because it represents a word-final consonant |z|, whereas in its Italian counterpart Maria canta, the corresponding third person singular inflection -a has greater phonetic substance because it is a full (i.e. unreduced) vowel The perceptual deficit which SLI children have means that they require many more exposures to a given ‘weak’ morpheme with little phonetic substance than a typically developing child in order to acquire it – though the perceptual deficit will be much less evident for ‘strong’ morphemes with more phonetic substance. This predicts (inter alia) that there should be a much greater difference between the performance of SLI and TD children on (e.g.) contracted forms of the copula than on full (uncontracted) forms. Moreover, as in typically developing children, grammatical processing (and hence the acquisition of grammatical morphemes) will take longer for more complex morphemes (e.g. those carrying more grammatical features) than for than less complex morphemes. This predicts that SLI children should acquire grammatical morphemes in the same order as TDs – but more slowly. Finally, a note on nomenclature. Leonard’s Perceptual Deficit account of SLI is frequently referred to under the alternative name of the Surface Hypothesis, since it assumes that surface (i.e. superficial perceptual) properties of morphemes determine how difficult they are to acquire. WORKBOOK SECTION Leonard’s core assumption is that perceptual factors play a key role in determining why SLI children have problems in acquiring phonetically insubstantial items – though he also acknowledges that grammatical processing plays an important part (with more complex items taking longer to process and acquire than less complex one). The exercises below are intended to get you to explore the relative roles of perceptual and grammatical factors in the acquisition of a range of different morphemes. §2.1 Comparing SLI and TD children Leonard (1992, 1995) reports on the results of a comparative survey of the grammatical performance of 10 SLI children (aged from 3;8 to 5;7) and 10 MLU-matched TD children (aged from 2;11 to 3;4), using data based on spontaneous speech samples. He presents the following figures showing the mean percentage of correct use in obligatory contexts for a number of grammatical phenomena by SLI and TD children: 15 Mean Percent Correct Use in Obligatory Contexts of Morphemes by SLI and TD children Item SLI children MLU-matched TD children regular past tense -d 32%28 65% irregular past tense verb forms 65% 77% regular 3Sg present tense -s 34% 59% 29 copula be 41% 71% auxiliary be 21% 46% auxiliary do 16% 27% noun plurals 69% 96% auxiliary inversion 66% 89% nominative case 62% 71% articles a/the 52% 62% infinitival to 34% 46% possessive ’s 32% 91% genitive of 47% 88% Discuss Leonard’s results, and how the Perceptual Deficit Hypothesis might account for them. Larry Leonard (pc) points out that noun plural -s is on average about 40% longer than (third person singuar) present -s, noting that this is due to the fact that the former appears in clause-final position more often than the latter, and that fricatives are lengthened in clause-final position. What is the significance of this observation, do you think? §2.2 Production of word-final consonants Paula Menyuk (1978) reported that SLI children have few problems producing a consonant at the end of a word when it is part of the stem of the word (as with the final |z| of nose), but have considerable problems producing a word-final consonant when it represents a grammatical inflection (as with the final |z| on a plural noun like bees). More specifically, she remarks (1978, p.147) that (in sentence-repetition tasks, where children are asked to repeat a word) ‘bees might be repeated as bee, but nose was never repeated as no’. Myrna Gopnik (1990, p.143) makes a similar point, observing that ‘The child who is presumed to have a perceptual problem with the final sound in boys has no problem with the word noise’. Leonard, McGregor and Allen (1992, p.1077) likewise report that ‘higher percentages of use are seen for [d] in braid than in played; similarly, percentages for [s] are higher in box than in rocks.’ What do you think are the implications of these findings for the Perceptual Deficit Hypothesis? §2.3 Sporadic omission and commission errors Gopnik (1990, p.144) reports that SLI children typically show sporadic (and sometimes inappropriate) production of grammatical morphemes like plural {s}. For example, she notes that an SLI child (PB) that she studied produced utterances such as the following: (a) (b) (c) When they play, get points. When the girls lose, are sad I was make 140 box. He only got two arena You got a tape-recorders. You make one points How far is PB’s performance on the italicised forms consistent with the Perceptual Deficit Hypothesis? 28 This figure indicates that the SLI children overall produced past tense -d in 32% of the contexts in which it would be obligatory for an adult English speaker to use past tense -d. 29 The word BE is said to function as an auxiliary when followed by a verb (BE is a progressive (aspect) auxiliary in He is waiting, and a passive (voice) auxiliary in He was arrested), and as a copula (i.e. linking verb) when followed by a non-verbal expression – e.g. by an adjectival expression like lazy as in He is lazy, by a prepositional expression like in Paris as in He is in Paris, or by a nominal (i.e. noun-containing) expression like a doctor as in He is a doctor. 16 §2.4 Performance on irregular pasts In a study of a different group of children, Ullman and Gopnik report (1994, p.111) that the SLI and TD subjects in their study perform just as well on regular pasts as on irregular pasts – and a parallel finding is reported in a study by Vargha-Khadem et al. (1995). To what extent are these findings consistent with the Perceptual Deficit Hypothesis? §2.5 Italian verb inflections Leonard (1989. p.197) reports that that Italian SLI children have greater problems in acquiring third person plural verb inflections than third person singular inflections. He notes (ibid.) that none of the eight Italian SLI children in his study used the third person plural inflection, and that all used the third person singular form of the verb in plural contexts (i.e. with plural subjects). The relevant forms for a regular verb like cantare ‘sing’ (whose stem form is cant-) are listed below (where |à| denotes a stressed vowel): canta [kànta] ‘sings’ (third person singular present tense = ‘He/She sings’) cantano [kàntano] ‘sing’ (third person plural present tense = ‘They sing’) To what extent is this finding predicted by the Perceptual Deficit Hypothesis? Why do you think ISLI children make this kind of error? §2.6 Morphological uniformity Jaeggli and Safir (1989, pp. 29-31) draw a distinction between those languages which are morphologically uniform, and those which are non-uniform. A uniform language is one (like Italian) in which (regular) words are of the form stem+affix and there are no regular words comprise simply a bare stem (without any overt affix); a non-uniform language is one like English in which some regular word forms (e.g. working) carry an overt affix and others (e.g. work do not). What role do you think morphological uniformity might play in accounting for differences between ISLI and ESLI children? §2.7 Verb-inflections and pro-drop A major typological difference between Italian and English can be illustrated by the following dialogue: SPEAKER A: Dove abita Maria? Where lives Maria? (= ‘Where does Maria live?’) SPEAKER B Abita a Milano Lives at Milan (= ‘She lives in Milan’) As these examples show, to refer to a person already mentioned, English requires the use of a pronoun like she in a sentence like that produced by speaker B. However, Italian is said to be a pro-drop language (or null-subject language), in that it allows a subject pronoun to be ‘dropped’ (i.e. omitted) or phonetically null (i.e. ‘silent’) if it refers to someone already mentioned (like Maria above) – and in fact we find the subject dropped in around two thirds of finite clauses in Italian. To what extent might this typological difference between the two languages account for the observation made by Leonard that Italian children perform better on producing inflected verbs than English children? §2.8 Grammatical complexity Rice & Oetting (1993) report that SLI children perform significantly better on plural -s than on 3Sg present -s: a group of SLI children they tested achieved 83% accuracy on noun plural -s but only 36% on 3Sg -s. How do you think the Perceptual Deficit Hypothesis might account for the relevant data? §2.9 Comprehension data Gopnik and Crago (1991) report that on a task testing comprehension of the noun plural -s morpheme, the SLI children in their study achieved the same scores as language-matched normally developing children. Children were given commands like ‘Please touch the book/the books’ to see whether they would touch a single book or more than one book. Gopnik and Crago (1991, p.36) conclude that ‘These results indicate that the subjects could perceive the difference between s-marked forms and unmarked 17 forms and could reliably associate this difference with number.’ What implications does this finding have for the Perceptual Deficit Hypothesis? §2.10 Production problems To what extent might Leonard’s findings about the problems which SLI children have with English inflections be attributable to production problems which SLI children are reported to have (e.g. by Fee 1994), particularly in producing syllable-final/word-final consonants? §2.11 Case and word order errors Loeb and Leonard (1991) report that children frequently use default (accusative) pronouns in contexts where adults require nominative pronouns, and hence say e.g. Him did it rather than He did it. Leonard (1995, 1281) reports that SLI children frequently fail to invert auxiliaries in questions, saying What Daddy’s doing? rather than What’s Daddy doing? (or alternating between the two). To what extent can such errors be attributed to a perceptual deficit? §2.12 Overall verdict What is your overall verdict on the strengths and weaknesses of Leonard’s Perceptual Deficit Hypothesis? 18 3. The Feature Blindness account of SLI Key article Gopnik, M. (1990) ‘Feature blindness: A case study’, Language Acquisition 1: 139-164 OUTLINE OF GOPNIK’S (1990) STUDY In her 1990 paper on feature-blindness, Myrna Gopnik argues that SLI is the result of a genetic deficit which prevents SLI children from acquiring grammatical features30 such as person, gender, number, countability, commonness, tense and aspect31. Gopnik claims (1990, p.139) that ‘These features are absent’ from SLI children’s grammars, and that consequently SLI children have ‘a grammar without syntactico-semantic features’ (1990, p.145). Gopnik maintains that the feature deficit is global in the sense that it affects all grammatical features. Methodology of Gopnik’s 1990 study Gopnik’s 1990 study is based primarily on data from a bilingual (French-English) Canadian boy from Québec (identified simply as PB) aged 8-9 years (for details of PB’s history, see Gopnik 1990, p.163-4). The data come from a mixture of spontaneous speech samples, prompted storytelling, repetition tasks and grammaticality judgements. The main errors reported in Gopnik’s (1990) study are summarised below. Number errors Gopnik notes that PB frequently makes errors with number-marking on nouns – e.g. he uses plural noun forms in singular contexts32 as in (1a), and conversely uses singular nouns in plural contexts as in (1b): (1)(a) You got a tape-recorders (b) He only got two arena Gopnik concludes from examples like these that the grammatical feature (singular/plural) number is absent from nouns in PB’s grammar, and that PB treats singular nouns like tree and plural nouns like trees as forms which are intrinsically unspecified for number (hence which can be used in singular and plural contexts alike). More specifically, Gopnik claims (1990, p.148): The feature deficit hypothesis provides a single coherent explanation for the data. Without the feature [plural], the s cannot be generated in the morphological component nor can feature-matching33 between the noun and the determiner operate. In this child’s grammar, s is regarded as a variant phonological form with no associated meaning.’ In other words, Gopnik claims that SLI children assume that tree and trees are two alternative (entirely equivalent) forms of the word TREE and hence can be used interchangeably (like e.g. dad and daddy). Gopnik claims that a similar number blindness is revealed by PB’s treatment of nouns on grammaticality judgements, repetition tasks, and writing tasks (see Gopnik 1990, pp. 148-9 for relevant data). She also reports (1990, p.148) that ‘Errors in number also occur with pronouns. He, it and they occur in spontaneous speech but are not reliably used to distinguish between singular and plural referents.’ 30 Gopnik uses the more cumbersome term syntactico-semantic features: by this she seems to mean what Chomsky (1995) calls formal features, and what I shall here refer to by Brown’s (1973) more traditional label grammatical features. 31 Person is illustrated by the I/you/he contrast; gender by the he/she/it contrast; number by the dog/dogs contrast; countability by the two chairs/*two furnitures contrast; commonness by the contrast between the chairman and *the Richard; tense by the goes/went contrast; and aspect by the contrast between going/gone (going marking progressive aspect and gone perfect aspect). Although she does not specifically mention case, presumably Gopnik would posit that the case errors made by SLI children (e.g. saying Me want one rather than I want one) are further instances of an overall grammatical feature deficit. 32 A singular/plural context is one in which an adult would require a singular/plural form. 33 By feature-matching, Gopnik means number concord between a determiner/quantifier and a noun which it modifies (so that a noun is marked as plural if modified by a plural numeral like two and as singular if modified by a singular numeral like one – cf. one dog/two dogs). 19 Commonness errors In English (and other languages) there is a distinction between common nouns on the one hand and proper nouns (also called proper names) on the other. Common nouns like man can generally be modified by a determiner like the, but proper names like Andrew cannot (hence we say the man but not *the Andrew34). Gopnik claims that PB shows no awareness of the distinctive properties of proper nouns and so treats them like common nouns, incorrectly using the to modify proper names like Red Riding Hood in sentences like: (2) The Red Riding Hood arrive at his grandma’s house Countability errors The set of common nouns can be further differentiated into two different subtypes, namely count nouns on the one hand, and mass nouns (or non-count nouns) on the other. Count nouns like chair have the property that they can be counted (cf. one chair, two chairs, etc.), whereas mass nouns like furniture are so called because they denote an undifferentiated mass which cannot be counted (cf. *one furniture, *two furnitures). Gopnik reports that PB confuses count nouns with mass nouns: for example, he uses (invariable) mass nouns like music as count nouns, pluralising them as in (3a) below; conversely he uses a singular count noun like bicycle (which, like all singular count nouns in English, would normally have to be modified by a determiner such as a/the/my/this etc.) as a mass noun (e.g. in contexts where adults would use a mass noun like cycling) as in (3b): (3)(a) I play musics (b) I love bicycle Gopnik concludes from examples such as (2) and (3) that PB has not mastered the commonness or countability properties of nouns: this, she claims, supports her more general hypothesis that PB has a global grammatical feature deficit (or, in her terms, is ‘blind’ to grammatical features)35. Gender errors Third person singular pronouns like he/she/it in English encode grammatical gender features, with it encoding so-called neuter (or inanimate) gender, and he and she respectively denoting masculine and feminine animate entities. PB produces a number of gender errors in pronouns, e.g. using he to refer back to an inanimate antecedent, as in: (4) When the cup break he get repair Here, PB fails to match the gender of the (animate) pronoun he to that of the inanimate expression the cup which it refers to. This (in Gopnik’s view) shows that he is blind to features like gender. Aspect errors In adult sentences such as He is going home, the sequence is going marks progressive aspect (i.e. indicates an action in progress): in this use, BE is a progressive auxiliary and the -ing form of the verb is a progressive participle36. Gopnik observes that in contexts where adults would use progressive BE with a verb in the progressive participle (-ing) form, PB may omit either BE as in (5a) below, or -ing as in (5b): (5)(a) This one is look (b) The dragon drying hisself Gopnik (1990, p.157) hypothesises that in adult progressive sentences like He is sleeping, both the auxiliary is and the verb sleeping carry an aspectual feature [Progressive-Aspect], and that there is a feature-matching requirement for the aspectual feature of the auxiliary to match that of the verb (so that a sentence denoting an action in progress requires use of both a progressive auxiliary and a progressive 34 Unless the proper name is modified by an expression such as that I once knew. Some nouns like daddy can function both as common nouns (as in ‘You can be the daddy’) and as common nouns (as is ‘Daddy is naughty’). 35 If it is a characteristic of mass nouns that they have no intrinsic number features, PB’s confusion over the countability properties of nouns will reduce to confusion over their number properties. 36 When not used in conjunction with BE, the ing-form of the verb generally functions as a gerund, e.g. in sentences such as He enjoys playing tennis. In adult English sentences such as He has gone home, the auxiliary HAVE marks perfect aspect (in that it marks the perfection – in the sense of ‘completion’ – of an action): however, Gopnik says nothing about perfect aspect. 20 verb-form). She maintains that the progressive aspect feature is absent from PB’s grammar, with the consequence that the feature-matching requirement does not hold – and so some sentences produced by PB like (5a) contain a progressive auxiliary (is) without a matching progressive verb-form (looking), while others like (5b) contain a progressive verb-form (drying) without a matching progressive auxiliary (is). Tense errors Gopnik claims that PB generally fails to mark tense in obligatory contexts37. For example, she notes (1990, p.153) that for PB ‘Regular past tense forms never occur in spontaneous speech’. So, in a sentence such as (6) below containing a past time expression like last time, the regular verb arrive appears as a bare (i.e. uninflected) form which lacks the past tense suffix -d: (6) Last time we arrive Gopnik administered an elicitation task to PB, asking him to convert present-tense sentences containing the word today into past-tense sentences containing yesterday: in 27/29 cases where PB’s response was unambiguous, it contained a bare verb form uninflected for past tense38. Similarly, Gopnik (1990, p.154) observes that ‘PB virtually never added s to the verb to mark the third person singular present’ – hence the absence of -s in a present-tense context in sentence (7) below: (7) He look at the other side of the tree And in a sentence-repetition task, PB omitted the s-inflection from 16/19 (84%) s-inflected present tense verb forms39. Pro-drop errors Gopnik notes that PB sometimes omits subject pronouns (a phenomenon widely referred to as pro-drop), reporting (for example) that in a sentence repetition task, PB dropped the subject in 4/16 (25%) test sentences. She argues that PB only omits subjects when he also omits tense-marking from verbs, her hypothesis being that ‘subject pronouns can be dropped’ when ‘the feature [tense] is not present’ (1990, p.158)40. For example, in a sentence repetition task, PB dropped the subject in 4/16 (25%) test sentences. WORKBOOK SECTION Gopnik’s key claim is that SLI children have a genetic deficit which makes them blind to (and hence completely unable to acquire) any kind of grammatical features, with the resulting feature blindness leading to a global grammatical deficit (i.e. an inability to acquire any grammatical feature of any kind). However, there are a number of aspects of her feature blindness analysis which seem questionable. For example, while it may well be the case that SLI children have problems in processing and acquiring grammatical features, it could be argued that this results in them being slow to acquire grammatical features and in marking them sporadically – rather than (as Gopnik claims) in being completely unable to acquire grammatical features and hence never marking them. Moreover, subsequent research has suggested that the feature deficit in SLI children may be selective rather than global, in the sense that SLI children have more problems with some kinds of features (e.g. agreement features) than with other others. The questions and exercises below are designed to get you to take a more critical look at Gopnik’s feature 37 I.e. in contexts where it would be obligatory for an adult to use a present-tense or past-tense verb/auxiliary. The two correct responses were unspecified irregular verb forms. Gopnik also counts ambiguous forms like He cut the grass as ‘correct’ past-tense responses: but this is inappropriate since it is impossible to be sure whether in such cases cut is a bare stem/infinitive form or a past tense form. I have excluded the four such ambiguous cases from the figures presented here. 39 The fact that PB correctly repeated 3/19 (16%) s-forms should not necessarily be taken as an indication that he is beginning to acquire third person singular present tense -s. Gopnik makes the point that the ability to correctly repeat a handful of model sentences may tell us very little about grammatical competence, particularly where the model sentence is short, since ‘Short sentences can be repeated directly from memory’ (1990, p.157). 40 More specifically, following Guilfoyle (1984), Gopnik suggests that pronouns can only be dropped when they cannot be case-marked: if the subject of a tensed clause (i.e. a clause containing a present or past tense verb/auxiliary) is assigned nominative case, it follows that the subject of a tensed clause cannot be dropped. 38 21 blindness model, and at just how strong the evidence is which she adduces in support of the model. But first, an exercise to test whether you understand the nature of the claims made by Gopnik. §3.1 Analysing sentences produced by PB The data below are examples of PB’s speech production (and grammaticality judgements) reported in Gopnik (1990). In examples containing italicised pronouns, the expression which the pronoun refers back to is bold-printed. (8-10) are examples of French (or mixed French/English) sentences produced by PB. (Abbreviations used below are: M = masculine, F = feminine, Sg = Singular and Pl = Plural.) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) You make one points I was make 140 box The dragon jumping One machine clean all the two arena41 The Marie-Louise look at the bird When the bus goes fast, he has an accident The Red Riding Hood arrive at his grandma’s house. Il prend un gros respiration He takes a-M.Sg big-M.Sg breath-F.Sg La mère, il prend le garçon The-F.Sg mother-F.Sg, he-M.Sg takes the-M.Sg boy-M.Sg ‘The mother, he takes the boy’ Puis après il cook le marshmallows Then afterwards he cook the-M.Sg marshmallows-M.Pl Discuss the nature of the errors made by PB in these sentences, and say how Gopnik’s feature-blindness model would account for each of the errors. If you know French, discuss the extent to which some of the relevant errors may be the result of transfer from French (given that PB is a French-English bilingual), and discuss the methodological issue which this raises. §3.2 A methodological issue Although Gopnik claims that PB shows a deficit in respect of grammatical features, she presents no systematic quantitative data42 relating to the frequency of the errors she discusses in naturalistic samples43 of PB’s speech (e.g. on the relative frequency of structures like two cars and two car, or on the relative frequency of one car and one cars). To what extent do you think this is a methodological weakness – and if so, why? §3.3 Rice and Oetting’s study Rice and Oetting (1993) report on a study they undertook of 81 SLI children 5 years of age and 92 MLUmatched normally developing (=ND) children (around 3 years of age). One of the phenomena they studied was number marking on nouns. They report that only 4/152 (2.6%) of the plural nouns produced by the SLI children in their study occurred in singular contexts (e.g. one dishes, it toys44), compared to 3/93 (3.2%) of the plural nouns produced by the TD children: by contrast, the SLI children in Rice and Oetting’s study showed more frequent use of bare nouns45 in plural contexts (53/404 = 16%) than TDs (38/473 = 7%), with almost all such errors involving quantifier+noun structures like two eye46. To what extent are these findings compatible with the Feature Deficit Hypothesis? 41 This is reported by Gopnik to have been produced in a present-tense context. More particularly, she presents no quantitative data on PB’s spontaneous speech output, even though she does present limited quantitative data in relation to other types of speech output (e.g. from elicitation tasks). 43 A naturalistic speech sample is a sample of the spontaneous speech (or ‘free speech’) of one person in conversation with another (the other person often being an interviewer/researcher). 44 Corresponding to the adult form ‘It’s a toy’. 45 I.e. uninflected nouns not carrying the plural -s affix. 46 This is arguably because number is marked by the use of the dual numeral two, and hence marking number on the noun is (in some informal sense) redundant. More generally, it may be that (more frequently than their TD 42 22 §3.4 On the nature of the feature deficit in SLI children SLI studies typically report that SLI children perform much better on some morphemes than on others. For example, Rice and Oetting (1993) report that SLI subjects performed almost as well on plural -s as MLUmatched TDs (83%/93%), but performed much worse on 3Sg -s than the TDs (36%/83%). To what extent do Rice and Oetting’s findings challenge the feature-blindness view of SLI? What if we modified Gopnik’s theory in such a way as to claim that it’s not impossible for SLI children to acquire and process grammatical features, but rather that they are very slow to process and acquire such features. Because of the processing load which features pose for an SLI child with a slow processor, the more features a morpheme marks, the more difficult it is to acquire and the longer it takes SLI children to acquire it. To what extent would this revised slow processor model account for Rice and Oetting’s findings? And to what extent would it account for the sentences produced by PB in §3.1? §3.5 On the nature of PB’s tense errors Gopnik’s Feature Blindness theory predicts that SLI children are blind to (and hence unable to acquire) grammatical features, including tense features. Which of the following five types of italicised verb form would her theory predict that SLI children produce in past tense contexts – and why? 1. Daddy went/go/goes/gone/going to Paris yesterday Compare this prediction with the observations which Gopnik makes about the range of verb forms which PB uses in past tense contexts. One observation she makes is that ‘Regular past tense forms never occur in spontaneous speech’ (i.e. he uses bare forms like play rather than past forms like played in past contexts), but elsewhere (1990, p.155, Table 8) she reports that PB produced 5 correctly inflected regular past tense forms on a writing task, and that he also produced some present-tense s-forms on a writing task. She notes that ‘frequent irregular past tense forms do’ get used by PB in past contexts47. On a tense transposition task (in which PB was asked to transpose a present-tense sentence containing today into a past tense sentence containing yesterday), PB produced two irregular past tense forms (though no regular past tense forms). In addition, we find the following two (italicised) irregular past tense forms produced by PB cited in Gopnik’s text: (a) I was make 140 box (b) Who did that? She also notes (1990, p.154) that in his speech production PB ‘virtually never added s to the verb to mark the third person singular present’ – though the text of her paper cites him producing the following example: (c) When the bus goes fast, he has an accident The text also shows PB producing a number of structures such as those below in which he uses appropriate present-tense forms of BE in present-tense contexts: (d) The witch is coming (e) I am riding a bicycle (f) All the girls sing and they are dancing To what extent are such data consistent with Gopnik’s feature-blindness view of SLI on which children like PB are completely blind to grammatical features like tense? §3.6 The nature of tense omission errors Gopnik maintains that PB has a defective syntax, and claims that his omission of present tense -s and past tense -d on regular verbs in obligatory contexts shows that verbs are not marked for tense in the syntax. However, an alternative view of the inflectional errors made by SLI children is that their syntax is relatively unimpaired (so that verbs are correctly marked as present/past tense in the syntax in appropriate contexts) but that they have morphological problems which mean that they sometimes fail to spell out the tense feature on a verb (or, informally, they sometimes ‘forget’ to add the appropriate inflection on the end counterparts) SLI children tend to omit grammatical features when they are redundant (i.e. when the relevant features make no essential contribution to determining meaning). 47 Presumably by this she means that high-frequency irregular past tense forms like went/came are used by PB. 23 of a verb to mark its tense). Gopnik assumes that the subject of a verb which is marked for present/past tense in the syntax is assigned nominative case (and hence is spelled out as a nominative form like I/he rather than as an accusative form like me/him). In the light of this assumption, consider the nature of the tense errors made by PB on the italicised verbs in the following sentences: (a) (b) When the cup break, he get repair I wait in the Berri-de-Montigny48 §3.7 On the nature of pro-drop Gopnik observes that PB sometimes omits subject pronouns in obligatory contexts (i.e. in contexts in which adults would require the use of an overt subject pronoun like I/you/he etc.): this phenomenon is traditionally referred to as pro-drop49. She suggests (1990, p.158) that ‘subject pronouns can be dropped’ when ‘the feature [tense] is not present’: what this implies is that if (in reply to a question like Where did Jamie go?) an SLI child uses a tense-marked verb like (past-tense) went, the child will use a subject pronoun and say ‘He went home’ (and will not omit he). But if the child uses a tenseless verb form like go, he can omit the subject pronoun and simply say Go home. What problems are posed for this claim by the fact that PB omits subject pronouns in English/French sentences such as those below? (a) (b) Can watch them at the Forums Ramène le feu Returns the fire (‘He brings the fire back’) More recent work by Liliane Haegeman and Luigi Rizzi (outlined in the collection of papers in Friedeman and Rizzi 2000) maintains that in cryptic styles of spoken/written adult English, a weak (i.e. unstressed or unemphatic) subject pronoun can be undergo a process of TRUNCATION whereby it is truncated (i.e. dropped) when it is the first word in the main clause of a sentence50, resulting in subjectless sentences such as Can’t find my wallet. Don’t know where I left it51. Must be at home. What bearing might this have on sentences like (a/b)? §3.8 PB’s aspectual errors What kind of errors does Gopnik’s feature blindness model predict that PB will make in marking progressive aspect? Is PB’s predicted behaviour consistent with his reported behaviour on an elicitation task, in which he was asked to describe the actions of hand puppets? On the relevant task, he produced 19 structures classified by Gopnik as obligatory contexts for marking progressive aspect, 7 like (a) containing both BE and -ing, 6 like (b) containing only -ing, and 6 like (c) containing only BE: (a) The queen is sleeping (b) The dragon jumping (c) The dragon is walk Could we account for the relevant pattern of errors rather better if we made the traditional assumption that SLI children make sporadic omission errors, but almost never make commission errors? 3.10 Overall verdict What is your overall verdict on the strengths and weaknesses of Gopnik’s (1990) feature-blindness paper? 48 Berri-de-Montigny is a metro/underground train station. This sentence was used to describe an event which had taken place the previous year. 49 An alternative terminology which is frequently employed is to say that children use null subjects in contexts in which adults require weak overt subject pronouns (so that apparently subjectless sentences contain a ‘silent’ subject pronoun which has no overt phonetic form, but has the same semantic/grammatical properties as weak pronouns). 50 In terms of the analysis in Rizzi (2000), a weak subject pronoun can have a null spellout when it is the specifier of a root (i.e.) main clause. For clarity, I present his proposal in a simplified (hence somewhat inaccurate) form. In the written language, subject-drop is found mainly in so-called diary styles, which is why the phenomenon is sometimes referred to as diary-drop. Spoken French allows a more restricted form of subject-drop, in which a ‘meaningless’ (non-referential) expletive subject pronoun can be dropped – as in the title of the French TV programme Faut pas rêver ‘Needs not dream’ = Il faut pas rêver ‘It needs not dream’ – i.e. ‘You don’t have to dream’ 51 Note that because it is not the first word in the sentence, the I subject of left cannot be dropped. 24 4. The Rule-Deficit Account of SLI Key article Gopnik M & Crago MB (1991) ‘Familial aggregation of a developmental disorder’, Cognition 39: 1-50 OUTLINE OF GOPNIK AND CRAGO’S STUDY Gopnik and Crago (henceforth abbreviated to GC) report on research into three generations of a family living in the East End of London (known as the KE family), 16 out of the 30 members of which are dysphasic (i.e. have SLI). Their research hypothesis (1991, p.12) is that dysphasics are ‘impaired in only one subpart of the grammar and have other parts of the grammar intact’. More specifically, they argue that dysphasics have essentially the same syntactic abilities as MLU-matched controls but have a genetic deficit which makes them unable to construct regular morphological rules: consequently they can only learn morphology by memorising individual word-forms. Accordingly, GC claim (1991, p.47) that dysphasics ‘have a learning mechanism that sees each word as an independent item that must be learned and entered into a lexicon that specifies its grammatical properties and meaning.’ Background: Dual mechanism model GC’s paper assumes the dual mechanism model of the acquisition of morphology (outlined e.g. in Pinker and Prince 1988 and Pinker 1991). Within this model, irregular forms are memorised forms which are stored/listed in the mental lexicon52, whereas regular forms are computed or derived via application of morphological rules like those sketched informally in (1) and (2) below which say how regular verb/noun forms are derived by adding particular affixes (more precisely suffixes) to the stem form53 of the item: (1) A regular verb carries the suffix: {s} if third person singular present {d} if past/perfect/passive {ing} if progressive/gerund {ø} otherwise (2) A regular noun carries the suffix: {s} if plural {ø} otherwise So, for example, the lexical entry (i.e. entry in the dictionary) for the regular noun BOY will contain simply the stem form boy: its plural will be formed by adding the suffix -s to the stem form in accordance with the first line of rule (2), so deriving boy-s; its singular form will be generated by adding the null suffix -ø in accordance with the second line of rule (2), generating boy-ø 54. By contrast, the lexical entry for the irregular noun MAN will contain not only the singular form man but also the irregular plural form men: the presence of the irregular plural form men in the lexicon will then block application of the regular plural formation rule (1i), so accounting for the ungrammaticality of *mans as the plural of man55. Similarly, the lexical entry for a regular verb like PLAY will specify simply that it has the stem form play, and regular morphological rules will determine that its third person singular present tense form is derived by adding -s to the stem form in accordance with the first line of rule (1), its past tense and perfect/passive participle forms are derived by adding -d56 in accordance with the second line of rule (1), its progressive participle 52 Using this terminology, we can draw a distinction between stored (i.e. memorised irregular) forms and derived or computed forms (i.e. rule-generated regular forms). 53 What is here referred to as the stem form generally corresponds to the citation form found in dictionaries. 54 Underlying the last line of rule (1) is the traditional idea that seemingly uninflected forms (i.e. forms which have no overt inflection) contain a null affix (traditionally called a zero morpheme). If we made rather different assumptions, we could take the last line of rule (1) – and likewise the last line of rule (2) – to mean that the relevant form is derived by adding no suffix to the stem form of the relevant item. 55 If man is listed in the lexicon as the stem form, the singular form man will be derived by the addition of a null affix in accordance with the second line of rule (2). 56 The past tense form occurs in sentences such as He played tennis yesterday, the perfect participle form in sentences such as I have never played squash, and the passive participle form in sentences such as The game was played in a spirit of competitive camaraderie. Note in particular that the participle form used with the auxiliary have is a perfect participle in English, and not (as in languages like French) a past participle. Because French does have genuine past participles, it can use the relevant participial structures in genuine past tense contexts – e.g. J’ai vu 25 and gerund form is derived by adding -ing in accordance with the third line of rule (1), and its other inflected forms are derived by the addition of a null affix -ø in accordance with the fourth line of rule (1)57. By contrast, the lexical entry for an irregular verb like GO will specify that it has the stem form go, the irregular perfect participle form gone and the irregular past tense form went; it will follow from this that its (regular) third person singular present tense form is derived by adding -s to the stem form (giving goes) in accordance with the second line of rule (1), its (regular) progressive participle form by adding -ing to the stem form (giving going) in accordance with the fourth line of rule (1), and its other forms by adding the null affix -ø to the stem form (giving go+ø) in accordance with the last line of rule (1)58. Methodology of Gopnic and Crago’s (1991) study GC provide comparative data on 6 dysphasic59 members of the KE family they studied (aged 16, 17, 40, 42, 45 and 74), and 6 unaffected members (aged 8, 12, 13, 14, 15 and 17). For 10 of the 12 subjects GC’s data come from comprehension and production tasks administered to them, but for the remaining 2 (dysphasic) children the data come from school compositions written by the children once a week. Test results GC report that there was no significant difference between the performance of the dysphasic members of the family and the unaffected members on tests involving grammatical comprehension or grammaticality judgements relating to co-ordinate structures60, negative active and passive sentences61, possessive constructions62, argument structure63, pronoun reference64, gender65, and number66. From this, they conclude that there is no global impairment of grammar in the dysphasic members of the family. However, on 5 other tests, the SLI family members performed significantly worse than the normals. One Marie hier (literally I’ve seen Marie yesterday, idiomatically ‘I saw Marie yesterday’), whereas English perfect participles (because they mark perfect aspect and not past tense) cannot be used in a past tense context (e.g. in a sentence containing an adverb like yesterday). 57 Hence the form play-ø would occur e.g. as an infinitive form in I want to play, a subjunctive form in They insisted that he play the national anthem, an imperative form in Play it again, Sam! and a present-tense indicative form in They never play our tune. As pointed out in footnote 54, we could alternatively assume that bare forms like these contain no affix rather than a null affix. 58 Note that an important implication of this assumption is that an irregular verb like GO is typically irregular only in some (i.e. one or more) of its forms, but regular in others. 59 Recall that Developmental Dysphasia and Specific Language Impairment are equivalent terms: hence a developmental dysphasic is an individual who has SLI. 60 Like ‘Here are 3 crayons. Drop the yellow one on the floor, give me the blue one and pick up the red one.’ 61 Subjects were shown two pictures, one of a truck pulling a car and the other of a car pulling a truck, and were tested on sentences like ‘The truck does not pull the car’ and ‘The truck is not pulled by the car’. 62 Subjects were shown a picture (e.g.) of a mother pushing a baby in a carriage and asked to ‘Show me the mother’s baby’ or ‘Show me the baby’s mother’. 63 In a sentence like The prisoners escaped, the verb escaped is said (in traditional work in Predicate Logic) to function as a predicate which has a single argument (its argument being its subject the prisoners). In a sentence like The police arrested a suspect, the verb arrested has two arguments, namely its subject the police and its complement a suspect. In John sent a parcel to Mary, the verb sent has three arguments, namely its subject John, and its two complements a parcel and to Mary. In the argument structure sentences given to the family members, they were asked to judge the grammaticality of 5 incorrect and 6 correct sentences: the incorrect sentences had argument structure errors, as in He eats a cookie to the boy and The boy puts the book. 64 Subjects were tested for whether they treated two pronouns as coreferential (i.e. as referring to the same individual) in sentences like ‘He washes himself’ on the one hand and ‘He washes him’ on the other. 65 Subjects were shown pictures of a man holding another man, a man holding a woman, a woman holding a man, and a woman holding another woman and asked to point to the picture which can be described by saying e.g. ‘He holds her’. 66 In one test, subjects were shown 16 objects (4 books, 4 crayons, 4 coins and 4 balloons) placed on a table in front of them; the objects were randomly arranged in 8 piles, with each pile containing either a single item or 3 items of the same kind. They were then given commands such as ‘Please touch the book’ or ‘Please touch the books’. In a second test, they were asked to perform more complex tasks like ‘Put the crayon on the balloons’. 26 was on a test eliciting plurals of novel words67 (normals achieving a mean score of 83% correct and dysphasics 47%). Another was on a grammaticality judgement test in which subjects were asked to judge whether 9 correct and 21 incorrect test sentences (containing person/number/tense/aspect errors68) were grammatical or not: the normals achieved a mean score of 92% correct judgements, and the dysphasics 57%. A third was on a test of their ability to produce verbs inflected for tense and aspect: normals achieved a mean score of 72% correct, and dysphasics 30% correct69. A fourth was on a derivational morphology task70 in which the normals achieved a mean score of 95% correct and the dysphasics 29%. A fifth was on a narrative task in which the subjects were shown 6 cartoons and asked to tell the story they depict: they were then scored in respect of the percentage of their referring expressions (i.e. the expressions they used to refer to characters in the cartoons) which were pronouns (like he) or noun expressions (like the man); normals showed 45% mean use of pronouns71, and dysphasics 9% (so that the dysphasics used far fewer pronouns and far more noun expressions than the normals). In addition, GC note that the dysphasics took significantly longer to respond to test stimuli than the normals: for example, the mean response time for normals on the grammaticality judgement test for person/number/tense/aspect was 52 seconds for the normals and 112 seconds for the dysphasics. GC also note that the dysphasics reported that they found such judgement tasks very difficult, making remarks like ‘I’m not sure if that’s right or wrong’. Gopnik and Crago conclude that the dysphasic members of the family show selective impairment of specific grammatical abilities. Results of the notebook study Data for two of the dysphasic children (a 10-year-old boy T and an 11-year-old girl C) came from their school notebooks. Every Monday throughout the school term, the children wrote a composition about what had happened over the weekend. T’s notebook contained 25 entries with a mean length of around 35 words, C’s contained 21 entries with a mean length of around 50 words. Gopnik and Crago scored the use of verb forms by the children, and report that they performed much better on irregular verbs than regular verbs (T/C correctly inflecting 80%/90% of irregular verbs and 31%/39% of regular verbs respectively). Gopnik and Crago’s conclusions Noting that their dysphasic subjects had problems in pluralising nonsense words, GC conjecture that the dysphasics lacked the regular plural formation rule (1i) which the normals had acquired. They account for the good performance of the dysphasics on tests of their comprehension of the singular and plural forms of real nouns by positing that dysphasics learn singular and plural forms of real words by memorising them (and thereby are able to produce and comprehend memorised forms of real words). What this means in more concrete terms is the following. For normal subjects, the lexical entry for a regular noun like BOY will contain only the stem form boy, with the plural form boys derived by application of the pluralisation rule (1i)72. By contrast, for dysphasics the lexical entry for the relevant noun will contain both the singular form boy and the plural form boys73, and they will have no counterpart of the pluralisation rule (1i) in their 67 Also referred to as nonsense words. In this test, the subjects were shown pictures of imaginary animals. The experimenter would point to a picture of an imaginary animal and say ‘This is a zoop’, and then point to a picture of 2 or 3 of the same animals and say ‘These are ...?’, inviting the subject to complete the sentence. 68 CG (1991, p.22) remark that their test sentences contained ‘errors in number The boy eats three cookie; person The boy kiss a pretty girl; tense Yesterday the girl pet a dog; and aspect The little girl is play with her doll’. 69 Subjects were asked to complete the second sentence in sequences such as ‘Every day he walks 8 miles. Yesterday he......’ ‘The boy always cries. Right now he.....’ ‘Yesterday the girl baked a cake. Tomorrow she......’ The percent correct use figures given here are based on the more ‘generous’ of the two scoring procedures outlined by GC. 70 Subjects were asked to complete the second sentence in sequences such as ‘There is a lot of sun. It is very...’ (to test whether they can form the adjectival derivative sunny from the noun sun). The figures given here are based on the more generous of the two scoring procedures suggested by GC (under which both proud and prideful would be taken as indicating that the subject can form an adjectival derivative of pride). 71 I.e. a mean of 45% of their referring expressions were pronominal, the other 55% being nominal. 72 Given the last line of the rule given earlier in (1) in the main text, the singular form boy will be derived by adding a null affix -ø to the stem form boy, forming boy+ø. 73 In other words, dysphasics treat regular plural nouns in the same way as normal adults treat irregular nouns like man/men. 27 grammar. More generally, GC hypothesise that dysphasics have a rule deficit which makes it impossible for them to form morphological rules, and conjecture that the deficit is genetic in nature. Predictions made by Gopnik and Crago’s analysis The assumption that dysphasics have a genetic deficit which makes it impossible for them to construct regular morphological rules makes a number of interesting predictions. One is that dysphasics will be unable to inflect novel words (e.g. unable to inflect a nonsense word like plam for past tense): this is because past tense formation in normal adults requires you to: (3)(i) (ii) Go to your mental lexicon, see if you have an irregular past tense form listed for the verb in question, and retrieve it if you have If not, apply the regular past tense d-formation rule in (1) Now, since your mental lexicon cannot in principle contain an entry for the past tense form of an invented nonsense word like plam, the only way of forming its past tense is to fall back on the regular past tense d-rule in (1): but since dysphasics (according to GC) cannot acquire regular morphological rules like (1), the Rule Deficit Hypothesis predicts that they will be unable to produce the appropriate past tense form plammed (and will instead just use the ‘bare’ uninflected infinitive plam). A second prediction which the Rule Deficit Hypothesis makes is that dysphasics will be unable to form over-regularised forms like (e.g.) past tense forms such as goed/comed/buyed/seed etc. This is for the following reason. When normally developing children want to use a past tense form of an irregular verb (say BUY), they will first (in accordance with (3i) above) go to their mental lexicon and see if it is a verb for which they have an irregular past tense form stored in their lexicon; if they haven’t yet learned the irregular past tense form bought (or have only just begun to learn it and still have problems retrieving it because they haven’t heard or used it often enough to be able to retrieve it unfailingly), they will fail to retrieve the adult irregular form bought and will instead fall back on (3ii), applying the regular past tense d-rule in (1), so producing the over-regularised form buyed. But because the Rule Deficit Hypothesis claims that dysphasics have a genetic deficit which makes them incapable of acquiring regular morphological rules like (1), they cannot in principle fall back on (3ii) and so will instead simply use the ‘bare’ uninflected form buy e.g. in sentences like Daddy buy me one yesterday. A third prediction which the Rule Deficit hypothesis makes is this. Since (by hypothesis) dysphasics have to memorise all inflected forms (regular and irregular alike), and since we know that memorisation improves with exposure and use (in the sense that the more often you are exposed to hearing other people use a given word-form, the more quickly you memorise it and the more easily you are able to retrieve it from your memory when you need it), this predicts that dysphasics will perform better on those forms which they hear more frequently than other forms. Since many of the most frequent past tense verb forms they hear and use tend to be irregular verbs like came/went, this might lead us to expect that dysphasics will generally perform better on irregular than regular past tense verb forms. Reasoning along similar lines, GC argue that the much better performance of the two dysphasics in the notebook study on irregular than regular past tense forms can be accounted for in terms of their rule deficit hypothesis. Irregular past forms are memorised, and listed as stored forms in the mental lexicon. Regular forms cannot be rule-generated (because the dysphasics lack the capacity to form morphological rules) and so can only be learned as memorised forms which are stored as such in the lexicon. Since memorisation requires considerable exposure to the relevant forms74, dysphasics will only be able to produce high-frequency inflected forms of regular verbs (i.e. verb forms which have a very high frequency of occurrence in the adult speech input which they receive)75. In support of this claim, GC note that of the 74 Recent work by Maslen et al. (2003) estimates that normally developing children need to hear a given verb-form (e.g. an irregular past tense form like ate) around 10,000 times (and make around 1,000 attempts at producing it) before they can consistently produce the relevant form without error. Presumably dysphasics require far greater exposure (perhaps twice as much). 75 GC (1991, p.41) conjecture that to memorize inflected forms (both regular and irregular) would take 30 or 40 years to accomplish, and even then is likely to be accomplished imperfectly. 28 11 regular verbs in the notebook compositions, only 4 were correct in their first occurrence (namely showed, asked, called and picked) and that three of these four verbs occur more frequently in past tense forms than in present tense forms76. WORKBOOK SECTION The key assumption in GC’s (1991) paper is that SLI children have a genetic deficit which makes it impossible for them to acquire regular morphological rules. However, one criticism which could be made of such a claim is that it is too extreme, and that rather than suppose that SLI children are unable to acquire regular morphological rules, we should instead suppose that they are much slower than typically developing children in acquiring morphological rules (in the same way as GC showed that their SLI subjects were twice as slow as their unaffected subjects in giving grammaticality judgments). This would allow for the possibility that a dysphasic (at a particular stage of development) may have acquired some but not all the regular morphological rules in a language (e.g. the noun-plural s-rule, but not the presenttense s-rule). The questions and exercises below are designed to encourage you to think more critically about a range of aspects of GC’s paper. §4.1 A methodological issue GC claim that close study of the weekly notebook compositions of two of the dysphasic children provides further evidence that the children acquire regular past tense forms by memorisation rather than ruleformation. For example, the first entry of the year in T’s notebook contains the following (verb forms used in past tense contexts being italicised): (a) On Saturday I watch TV and I watch plastic man and I watch football. On Sunday I had pork and potato and cabbage. The teacher corrects the entry by adding -ed to each occurrence of watch. T gets watched right the next time he uses it (5 weeks later) in the entry in (b) below, but does not add -ed to other regular verbs like wash and dress in contexts where -ed is required: cf. (b) On Saturday I got up and I wash my self and I get dress and I eat my breakfast and I watched TV all day and I went to bed. On Sunday, I got up and... Again, the teacher corrects the notebook, changing wash/dress/get/eat to washed/dressed/got/ate. Again T gets the corrected forms right in later work, and two stories later he writes: (c) On Saturday I got up and I got dressed 77 and I watched Motormouth...and I ate my dinner GC (1991, p.39) conclude that ‘The pattern throughout the year demonstrates clearly that the subject learns the individual past tense forms as they are corrected by the teacher, but does not generalize these corrections to new verbs’. What do you think are the potential methodological pitfalls of using evidence from a notebook study – and to what extent are the conclusions GC draw from the relevant notebook evidence justified? Can you offer an alternative accounts of T’s behaviour? §4.2 Ullman and Gopnik’s (1994) follow-up study In a (1994) follow-up study of the KE family, Ullman and Gopnik (henceforth UG) examined 10 of the family members (7 of whom had been diagnosed as language-impaired), testing their ability to form the past tense of 16 existing regular verbs (e.g. look), 14 existing irregulars (e.g. dig), 12 novel regulars (e.g. plam), and 14 novel irregulars (e.g. crive)78. Some of the dysphasic family members produced no novel They cite the following frequency data from Kucera and Francis’ (1957) frequency dictionary: ask = 128, asked = 398; call = 188, called = 401; pick = 55, picked = 78; show = 287, showed = 141. 77 The word dressed is not a past tense verb form, but rather a passive participle, perhaps used adjectivally. 78 Novel irregulars are nonsense verbs which might be expected to have an irregular past tense form by analogy with existing irregulars: e.g. we might expect the novel verb crive to have the past tense form crove by analogy with the existing (rhyming) irregular drive which has the past tense form drove. 76 29 regular past tense forms (e.g. plammed) at all and no over-regularised past forms (e.g. digged)79, although they did nonetheless produce past tense forms of some existing (regular and irregular) past tense verbs. To what extent is the behaviour of these family members consistent with GC’s Rule Deficit model? §4.3 Performance on novel words As noted above, GC report that their subjects achieve a significantly lower score on novel plurals than the normal family-members (47% compared to 83%). Ullman and Gopnik (1994) report that one member of the KE family (AD) produced 1 novel past tense form and a number of over-regularised past forms on a production task. In a similar vein, Vargha-Khadem et al (1995, p.931) report (in relation to a past tense production task with irregular verbs given to affected members of the KE family) that ‘Overregularisations constituted 41% of all errors’. To what extent are these findings consistent with GC’s hypothesis that dysphasics are unable to form morphological rules? What alternative possibility can you suggest? §4.4 Findings from other SLI studies Rice and Oetting (1993) report that the SLI subjects in their own study produced noun plurals like mans and pronoun plurals like herselves. Reporting on a case study of a 10-year old boy with SLI (identified as AZ), Heather van der Lely (1998, p 164) notes AZ producing nominals such as two foots and two mens, as well as sentences like This is what they ated. In a study of 12 SLI children ranging in age from 8;2 to 12;11, Dorothy Bishop (1994) reports that with existing irregular verbs in past tense contexts, the children (identified by letters and numbers) typically alternated between producing the correct irregular past form and producing a bare form: cf. (b) (c) Took it off (D17, in reply to ‘What did they do with the top part of the pram?’) It take me a long time (D17 in reply to ‘Did it take you a long time to get better?) Bishop also reports her SLI subjects producing over-regularised past tense/perfect participle forms like falled, losed, throwed, runned, and taked and the ‘doubly inflected’ forms sawed and broked: cf. (d) (e) (f) (g) And then Mummy taked to the garage to xxx (J03) He falled in (J03, reply to ‘What did Andrew do when the ice gave way?’) He sawed mine brother (J03, reply to ‘Has the doctor ever been to see you?’) The car has broked down (J03) In addition, Ramos and Roeper (1995) report on a 4-year old boy with SLI who shows 0% use of 3Sg present tense {s} and genitive {s}, while nonetheless using (and over-generalising) plural {s}, past tense {d} and progressive {ing}. Consider the implications of these various findings for the Rule Deficit Model of SLI. Could we provide a better account of the relevant data if we assumed that SLI children have a Generalised Morphological Deficit which causes them problems with acquiring and retrieving irregular forms, and likewise with acquiring and applying regular morphological rules (so that e.g. they sometimes under-apply the regular past tense d-rule it and fail to apply it to a regular verb, and conversely sometimes over-apply it and so wrongly apply it to an irregular verb)? How would such a model account for SLI children alternating (in past tense contexts) between forms like took, tooked, taked and take? §4.5 Performance of dysphasics on existing irregulars Ullman and Gopnik (1994) note that dysphasic members of the KE family had problems not only in producing past tense forms of existing regular verbs but also in producing past tense forms of existing irregular verbs: e.g. VA scored 0% correct on existing irregulars, ST 7%, KA 21% and AD 36%. They also report (1994, p. 111) that ‘Irregular pasts were not produced more successfully than regular pasts’. In much the same way, Vargha-Khadem et al. (1995) claim in relation to a past tense production task given to dysphasic members of the KE family (pp.930-931) that ‘Their impairment was equally evident on irregular forms…and regular forms’, further commenting in relation to irregulars that ‘The affected 79 Over-regularisation involves treating an irregular verb like dig (which has the past dug) as if it were regular and adding the regular past tense ending -ed to its stem, forming digged. 30 members were impaired to about the same degree on these as on the regular forms’. Discuss the implications of these findings for the Rule Deficit model of SLI. §4.6 Differential performance on inflections A number of studies report that SLI children perform much better on some inflections than on others. For example, Rice & Oetting (1993) report that a group of SLI children they tested achieved 83% accuracy on noun plural -s but only 36% accuracy on 3Sg -s. Likewise, Leonard (1989, p.181) notes that for the SLI children he studied, the morpheme -ing was ‘only slightly below expectations based on MLU’ (i.e. SLI children scored almost as highly on -ing as MLU-matched TD children); whereas Leonard (1995) reports only 32% and 34% correct use for past tense -d and present tense -s respectively. Likewise, Dorothy Bishop (1994) in a study of 12 SLI children ranging in age from 8;2 to 12;11 reports that her subjects achieved between 92% and 100% correct use of plural -s, but 67% correct use of 3Sg present tense -s. Discuss the implications of such studies for the Rule Deficit model of SLI. §4.7 Progressive structures The pattern of errors which GC (1991, p.41) report for progressive structures involves not only omission of the progressive morpheme -ing in structures like (a) below but also omission of the progressive auxiliary BE in structures like (b): (a) Carol is cry in the church (b) I walking down the road To what extent can the Rule Deficit model of SLI account for either or both of these errors? §4.8 Pronoun avoidance One of the findings of Gopnik and Crago’s study was that SLI-affected members of the KE family showed a much lower use of pronouns on the narrative task than the unaffected members, the affected members showing 9% mean use of pronouns, and unaffected members 45%. To what extent does their Rule Deficit hypothesis account for this finding – and (if not) how else do you think it might be accounted for? §4.9 On the nature of the impairment in members of the KE family Vargha-Khadem et al (1995, p.930) report that dysphasic members of the KE family showed ‘impaired processing and expression of other areas of grammar’ (they cite problems with processing relative clauses) ‘grossly defective articulation of speech sounds, and, further, a severe extralinguistic orofacial dyspraxia’ (the latter resulting in difficulty in performing actions such as clicking their tongue, humming a tune, biting their lip, licking their upper lip, smacking their lips, closing their left eye, sticking out their tongue etc.). In addition, they note that 6 of the affected members of the KE family have both verbal and performance Intelligence Quotient (IQ) scores below 85. What are the implications of these observations for Gopnik and Crago’s Rule Deficit account of SLI? §4.10 Findings of the Hurst study Hurst et al (1990) tested 4 language-impaired members of the KE family and found that they ‘took a long time to name pictures of objects with which they were familiar’ and sometimes produced inappropriate responses ‘for example glass or tea for cup, and sky for star.’ What implications (if any) do you think their observations might have for (e.g.) the poor performance of affected KE family members on the use of inflected forms (such as past tense verb forms)? §4.12 Overall Evaluation In the light of the questions raised above, what’s your overall evaluation of the strong and weak points of GC’s rule-deficit theory of SLI? 31 5. The Agreement Deficit account of SLI Key article Clahsen H, Bartke S and Göllner S (1997) ‘Formal features in impaired grammars: a comparison of English and German SLI children’, Journal of Neurolinguistics 10: 151-171 OUTINE OF CLAHSEN, BARTKE AND GÖLLNER’S STUDY Clahsen, Bartke and Göllner (henceforth CBG) use data from English and German children with SLI to argue that SLI involves a selective grammatical deficit. They claim that both the English and German SLI children in their study had far more problems in marking agreement than tense on (auxiliary and main) verbs. In the light of the claim in Chomsky (1995) that tense features on verbs are interpretable (i.e. they contribute to determining the meaning of sentences) whereas agreement features on verbs are uninterpretable (i.e. make no contribution to meaning), CBG conclude that SLI children have problems with acquiring uninterpretable features. Since understanding CBG’s work requires an understanding of the difference between interpretable and uninterpretable features, let’s begin by looking at this. Interpretable and uninterpretable features Consider the grammatical features80 encoded by she and is in sentence (1a) below, which include those given in (1b/c): (1)(a) (b) (c) He is in Paris he = [third-person, singular-number, masculine-gender, nominative-case] is = [third-person, singular-number, present-tense] In his (1995) book The Minimalist Program, Chomsky draws a distinction between interpretable features (i.e. those features which have semantic content and play a role in determining the meaning of sentences), and uninterpretable features (i.e. those features which have no semantic content and play no role in determining meaning, but rather simply serve some purely grammatical function). Chomsky maintains that the person, number and gender properties of personal pronouns in English (which he terms their φ-features ‘phi features’) are interpretable features, since a third person pronoun like he has a different meaning from a second person pronoun like you, a singular pronoun like he has a different meaning from a plural pronoun like they, and a masculine pronoun like he has a different meaning from a feminine pronoun like she. By contrast, Chomsky claims that (nominative/accusative/genitive) case features are uninterpretable81 – as we can illustrate in terms of the sentences in (2) below: (2)(a) (b) (c) I hadn’t expected [that he was announcing a takeover] I hadn’t expected [him to announce a takeover] I hadn’t expected [his announcing a takeover] The case properties of each italicised pronoun in (2) are determined by the position which it occupies in the syntactic structure containing it: the pronoun is nominative (he) in (2a) by virtue of being the subject of the agreeing (auxiliary) verb was; it is accusative (him) in (2b) because it falls within the domain82 of the transitive verb expect; it is genitive in (2c) because it is the subject of the gerund deciding (and the 80 Chomsky refers to grammatical features as formal features (since they play a role in determining the superficial form of words), and CBG use this term throughout their paper. I shall keep to the traditional (and more familiar) term grammatical features here. 81 More accurately, Chomsky claims that structural case features are uninterpretable. He draws a distinction between structural and inherent case, structural case being assigned to an expression by virtue of the position it occupies in the syntactic structure containing it, and inherent case being assigned to an expression by virtue of the semantic role it fulfils. Case in English is generally taken to be structural. 82 Informally, domain can be characterised as ‘sphere of influence’. More formally, it can be defined in terms of the relation c-command in ways which I will not explore here. 32 subject of a gerund in literary styles of English carries genitive case)83. In all three occurrences in (2), the pronoun he/him/his has the same meaning (i.e. it is a third person singular masculine pronoun), suggesting that case-features are uninterpretable and so play no role in determining the meaning of the pronoun. Now consider the features carried by the copular (i.e. ‘linking’) verb is in (1a) He is in Paris – shown in (1c) above. The present-tense feature carried by is must be an interpretable feature, since the meaning of the sentence changes if we replace the present-tense form is by its past tense counterpart was. By contrast, the person-number features of verbs are uninterpretable, since they are simply assigned to the verb via agreement with the subject: i.e. the [third-person, singular-number] features carried by the verb is in (1) He is in Paris are simply a copy of those carried by the subject he. As far as semantic interpretation (i.e. meaning) is concerned, it is the person/number/gender features of the subject he which are interpretable and so play a role in determining meaning (since they tell us that he refers to a single male entity which is neither speaker nor addressee), not the person/number features of the verb is (which are uninterpretable84). In the context of CBG’s paper, the important generalisations which come out of the discussion above are: (3)(a) (b) The (person/number/gender) phi-features of noun/pronoun expressions are interpretable, but their case-features are uninterpretable The tense features of verbs are interpretable, but their person/number (agreement) features are uninterpretable The English children studied by CBG The English data for CBG’s study come from elicitation tasks performed on a group of 9 SLI children in the age range 10;00-13;0185. On one task, the children were prompted to produce 3Sg present tense forms (using the prompt Every morning, my mum...), and on another to produce past tense forms (on a storytelling task using the prompt Once upon a time...). Both elicitation tasks were carried out twice for each child, at intervals of a year. On the basis of the responses the children produced, they were scored for their percent correct marking of case on subjects and tense/agreement on verbs. CBG report that the English children in their study achieved relatively high scores on the past tense elicitation task (overall86 correctly inflecting 76% of main verbs and 89% of auxiliaries for past tense in obligatory contexts), but much lower scores on 3Sg present tense forms (overall correctly inflecting 49%87 of main verbs and 35% of auxiliaries in obligatory contexts). They also report that the children achieved a 100% correct score on nominative case-marking in obligatory contexts (all 217 of their subjects being assigned nominative case, according to CBG). Conclusions drawn from CBG’s English SLI study The fact that the English SLI children achieved relatively high scores on past tense forms but much lower scores on 3Sg present tense forms leads CBG to conclude that the reason for their poorer performance on 3Sg present tense forms is the fact that the latter encode not only tense but also agreement in (person and number) phi-features with the subject. More specifically, they posit that SLI children have far greater problems in marking agreement (viz. between subject and verb) than in marking tense: since past tense 83 Simplifying somewhat, we can say that verbs carrying the inflection -ing are traditionally classified as progressive participles when used in conjunction with BE in sentences like He is lying, but as gerunds in other uses. The use of genitive subjects with gerunds is restricted to formal (e.g. literary) styles, colloquial English using accusative subjects with gerunds – as in ‘It was really upsetting, him not turning up to the party.’ 84 If we replace the third person singular form is by the first person singular form am, we don’t change the meaning of the sentence at all, but simply produce an ungrammatical sentence *He am in Paris. 85 The data originally came from a study conducted by Heather van der Lely, currently a professor in the Psychology Department at University College London. 86 I.e. if we aggregate the figures from the 1993 and 1994 elicitation tasks. 87 There seems to be inconsistency in the figures given by CBG: on p.155, they report that the children correctly inflected 40% of main verbs for 3Sg present -s in 1993 and 48% in 1994; yet over the page, they report that their aggregate score was 49%. There would seem to be a scoring error of some kind (perhaps in the aggregate figure). 33 forms generally encode only tense88, the SLI children achieve high scores on this (76% for main verbs and 89% for auxiliaries); since 3Sg present forms encode not only present tense but also agreement, the SLI children achieve much lower scores on this (49% on main verbs and 35% on auxiliaries). Why should SLI children have greater problems in marking agreement on verbs than in marking tense on verbs? CBG argue that this is a consequence of the tense features of verbs being interpretable and their (person/number) agreement features being uninterpretable, and of the particular problems which uninterpretable features pose for SLI children. However, CBG argue that it cannot be that all uninterpretable features pose problems for SLI children, since the case features of pronouns are uninterpretable, yet the English children in their study make no case-marking errors of any kind. They therefore conclude that it is specifically uninterpretable phi-features which pose problems for SLI children: since the uninterpretable person/number phi-features on verbs are agreement features, this amounts to claiming that SLI children have an agreement deficit. The German children studied by CBG CBG’s study also includes one-hour spontaneous speech samples from 6 German SLI children aged 5;87;11. They report that the German SLI children they studied showed 99% correct tense marking89, but only 64% correct marking of subject-verb agreement. They conclude (1997, p.157) that the relevant data support their hypothesis that ‘Agreement phenomena cause major problems for English and German SLI children’. They also report that the German SLI children generally show correct marking of number, gender and person on noun and pronoun expressions: since these are interpretable features90, this is consistent with their hypothesis that interpretable features pose few problems for SLI children. They also note that subjects are correctly assigned nominative case (which would appear to be consistent with their hypothesis that it is specifically uninterpretable phi features – e.g. agreement features of verbs – which are impaired in SLI, not uninterpretable case features)91. Tsimpli and Stavrakaki’s Uninterpretable Feature Deficit account In an (1999) paper, Tsimpli and Stavrakaki (= TS), propose the more general hypothesis that SLIs have problems in acquiring all uninterpretable features92: for succinctness, let’s refer to this as the Uninterpretale Feature Deficit Model/UFDM. TS adduce empirical evidence in support of UFDM from a study of a 5-year-old Greek girl with SLI called Eva. They claim that Eva has problems with agreement, 88 The one exception to this are past tense forms of BE, which inflect for both tense and agreement in standard varieties of English (were being used with second person or plural subjects, and was with other subjects). In some varieties of English, was is used with all choices of subject (cf. You was wrong and we was right). 89 This score is determined from their use of German preterite forms in obligatory contexts. 90 However, it is far from clear that gender features are always interpretable in German. For example, the noun Mädchen ‘girl’ is neuter in gender in German, but denotes a female entity. 91 However, CBG concede that the strength of this finding is weakened if (as they assume) nominative is the default case in German. Default case is the case assigned to an expression which could not otherwise be assigned case (i.e. which is not within the domain of any case assigner). For example, in a sentence such as the following (i) Me lie to you? Never! the subject me cannot be assigned case by the infinitive form lie, since infinitives do not case-mark their subjects in English: hence, the subject is assigned accusative case by default (as a way of ensuring that it gets case). CBG’s German SLI children produce infinitival main clauses such as: (ii) Der essen gänse ‘He eat.infinitive geese’ [= He eat geese] and the subject is assigned default case (which is nominative in German). CBG also discuss word order phenomena relating to the position of finite and nonfinite verbs in German, but their discussion raises a number of complex technical issues which it would take us too far astray to delve into here. 92 This possibility was envisaged in Clahsen, Bartkle and Göllner (1997, p. 153), but rejected by them in favour of their alternative view which sees SLI involving a selective deficit affecting only a subset of uninterpretable features – namely agreement features. 34 case-marking, definite articles and clitic pronouns93. For example, they report that Eva correctly marked subject-verb agreement in only 5/169 (3%) contexts with second person plural subjects; that she correctly marked (unambiguous) case on nouns in only 3/13 (23%) obligatory contexts; that she omitted 3Sg object clitics in 83/86 (97%) obligatory contexts; and that she omitted the definite article in 199/208 obligatory contexts (96%). Since case and agreement features are uninterpretable (and since TS take object clitics and definite articles to comprise sets of uninterpretable case and agreement features), these results are consistent with an inability to acquire all uninterpretable features. By contrast, they report (p.52) that ‘Eva’s performance on the Greek tense system shows mastery of the present-past distinction’ – and since tense is an interpretable feature, this observation is consistent with the view that interpretable features do not pose particular problems for SLIs. The overall conclusion which Tsimpli and Stavrakaki draw is that ‘Non-interpretable features are not part of the SLI grammar’ (op.cit p.78). WORKBOOK SECTION CBG’s paper argues that SLI involves a selective grammatical deficit which affects the ability of affected children to mark agreement. Moreover, they attempt to find a principled basis for this deficit in linguistic theory (in terms of Chomsky’s distinctions between interpretable and uninterpretable features, and between phi- and case-features). TS propose the more general hypothesis that all uninterpretable features are impaired in SLI grammars. But is the evidence in support of their claims persuasive? The questions and exercises below are designed to help you arrive at a reasoned answer to this question. §5.1 On description and explanation Any attempt to account for a set of findings about what SLI children do and don’t say must not only describe the relevant data adequately, but must also provide a principled explanation of the relevant data in terms of some relevant theory (whether of language, language acquisition, or language impairment). To what extent are CBG and TS successful in providing a principled theoretical explanation for their finding? §5.2 Nominative case assignment Finite verbs and auxiliaries in adult English require a nominative subject (e.g. the finite auxiliary has in He has left requires a nominative subject like he and cannot have an accusative subject like him). CBG (1997, p.158) account for this by supposing that a finite (auxiliary or non-auxiliary) verb94 has an uninterpretable case feature which they refer to as ‘Assign NOM’ (meaning ‘Assign the feature nominative-case to my subject’). Given their assumption about nominative case-marking, to what extent are CBG correct in saying that their model predicts that SLI children will make no case-marking errors in nominative contexts (i.e. in structures where adults would use a nominative subject)? §5.3 On SLI children’s pronoun errors In earlier work, Loeb and Leonard (1991) reported on a study of the acquisition personal pronouns by 8 English SLI children (in the age-range 4;0-5;0). Data were elicited from the children by using play activities, by asking them to tell stories about using picture cards and to describe photos, and (where necessary) by elicitation (e.g. trying to elicit the form is by saying ‘This shoe is dirty but...’ and pointing to a picture of a clean shoe). The children’s correct/incorrect use of the 3rd person singular animate 93 Clitic pronouns are weak/unstressed pronouns which have the property that they must cliticise (i.e. attach) to an appropriate kind of host (e.g. a finite verb). 94 A complication overlooked here is that within Chomsky’s CP/TP/VP analysis of clause structure, it is T which carries the relevant case feature rather than the verb itself – but this does not affect the point of principle raised here. 35 pronouns (he/she) was scored in relation to the number of errors the children made in respect of the case, number, person and gender of the pronoun95. The table below shows the raw number of pronoun errors made by the children in Loeb and Leonard’s study96: Raw number of pronoun errors made by the SLI children in Loeb and Leonard’s study Child Age MLU Case Gender Number Person Ca+Ge Ca+Nu SLI1 4;0 2.6 259 0 0 0 0 0 SLI2 4;3 2.8 30 0 0 0 1 4 SLI3 4;5 3.2 16 74 0 0 1 0 SLI4 4;4 3.5 180 0 1 0 0 0 SLI5 5;0 3.8 4 41 1 0 0 0 SLI6 4;3 4.3 70 0 0 0 0 0 SLI7 4;8 4.3 4 2 2 0 0 0 SLI8 5;0 4.5 5 16 0 0 0 0 Which aspects of Loeb and Leonard’s findings seem to prove problematic for CBG’s view that the core deficit in SLI children lies in their ability to process uninterpretable agreement features of verbs? Does TS’s view that SLI is characterised by an impaired ability to acquire all uninterpretable features fare any better in accounting for the data? Are there any findings which neither model can account for? Why do you think the children in Loeb and Leonard’s study made a large number of case errors, whereas the English children in CBG’s study did not? §5.4 Implications of other studies of inflectional morphology A number of other studies of SLI (e.g. Leonard 1989, 1995; Rice and Oetting 1993) have reported that SLI children (around the age of 5) tend to perform very well on noun plural forms (e.g. doggies) and on progressive -ing verb forms (e.g. playing), but less (than half as) well on past tense marking (for regular and irregular verbs alike). Are these findings consistent with the Agreement Deficit and/or Uninterpretable Feature Deficit accounts of SLI? §5.5 On interpreting CBG’s scores CBG report that the ESLIs in their study (in obligatory contexts) showed 76% suppliance of past tense marking on main verbs, but only 49% suppliance of third person singular present tense -s on main verbs, concluding from this that ESLIs have more problems with marking uninterpretable agreement features on verbs than with marking interpretable tense features. However, if we suppose that correct use of 3Sg Present -s requires three separate features (person, number and tense) to be marked and that these three features are independent of each other, and if we further suppose that the ESLIs in CBG’s study have a 0.76 probability of marking tense in obligatory contexts (i.e. they mark it in 76% of obligatory contexts), then it is necessarily the case that the ESLIs must be better at marking either person or number (or both) than at marking tense in order to account for their 49% suppliance of 3Sg Present -s. For example, if they perform at the same level on marking number as on marking person, we would need to assume that they have an 80% suppliance rate for person and an 80% suppliance rate for number in order to account for their 49% suppliance of 3SgPres -s (because the probability of them marking person, number and tense simultaneously in obligatory contexts for third person singular present tense -s would be 0.76 x 0.8 x 0.8 – i.e. 0.49). What are the implications of this observation for the Agreement Deficit model proposed by CBG (and for the Uninterpretable Feature Deficit model of Tsimpli and Stavrakaki)? 95 The concentration on third person singular pronoun forms was motivated by the fact that Loeb and Leonard were looking for a possible correlation between SLI children’s use of nominative he/she subjects and their use of s-marked third person singular present tense verb forms like plays or is. I focus here on the children’s production of pronouns, setting aside their production of s-marked verb forms. The gender errors made by the children typically involved using he in contexts where adults would use she. 96 The case errors reported in column 4 almost all involve the use of an accusative subject (e.g. Him can’t swim) in a nominative context. The final two columns show multiple errors: Ca+Ge = Case+Gender; Ca+Nu = Case+Number. 36 §5.6 A scoring issue: what’s right and what’s wrong In a study like CBG’s in which the evidence presented is quantitative in nature, it is important to be sure that scoring is accurate – i.e. in crude terms, to be sure that the right things are counted in the right way. In this connection, what is the potential significance of the following quotation from their paper (p.155)? ‘Twenty obligatory contexts for 3rd sg. forms of auxiliaries were elicited, but only 7 were correctly inflected (= 35%). The past tense task elicited 154 auxiliaries, 137 of which were correctly inflected (= 89%). Here are some examples of agreement errors on auxiliaries: (1) (a) they was (JS 10;10) (b) he don’t know (RJ, 11;11) (c) she do97 (AT, 13;01)’ §5.7 Verifying CBG’s figures I have gone through the corpus used by CBG, and below list all the examples of contexts where adults would require a 3.Sg present form of BE as a progressive auxiliary, HAVE as a perfect auxiliary, and DO as a tense auxiliary98. Contexts where adults would use a third person singular present form of the progressive auxiliary BE 1. Try get the cat, the man is99 (JW 11;03). 2. A horse is jumping over a gate (JS 11;10). 3. The boy’s picking it up for her (JS 11;10). 4. The boy’s trying to eat them (AZ11 12;03) 5. A boy is picking them up (RJ 12;11) 6. He’s jumping over a fence with a horse (AZ12 13;0) 7. A boy’s crying (AZ12 13;0) 8. The boy’s picking them up (AZ12 13;0) 9. Horse is jumping over a fence (CT 13;11) 10. The man climb…is climbing up the ladder to get a cat off the roof (CT 13;11) 11. He’s crying (CT 13;11) 12. She’s cuddling her teddy (SB 14;0) 13. He’s jumping over a…the gate (SB 14;0) 14. The boy’s posting it (SB 14;0) 15. The boy’s crying (SB 14;0) 16. She’s holding a doll (AT 14;01) 17. She’s going to pull her wellingtons off (AT 14;01) 18. The driver who drove it is fixing it (JS 9;10) 19. The bus is going down the road (AZ12 11;0) 20. And he’s trying to fix him (WL 11;05) 21. The apples are dropping out and the man picking them all up (AT 14;01) 22. And boy picking ’em up (JW 11;03) 23. He jumping over a gate (WL 11;05). 24. Apples fallen out on the boy who pinching them (JW 11;03) 25. The man taking the cat down on the ground (AZ11 12;03) 26. The dog taking slipper off him (AZ11 12;03) 27. Her hugging it (CT 13;11) Contexts where adults would use a third person singular present form of the perfect auxiliary HAVE 28. The doggy’s got his shoes (JS 11;10). 29. A dog’s got his shoe (AZ12 13;0) 30. The dog has took the shoe off him (CT 13;11) 31. The girl has fallen down and she’s broken her glasses (SB 14;0) What this child actually said was ‘She sometimes do some plays’. Excluded from the list here are uses of HAVE and DO as main verbs, and uses of BE as a copular verb. 99 I assume the adult counterpart would be: Trying to get the cat, the man is 97 98 37 32. The dog has got his shoe (SB 14;0) 33. The lady has got a bag and it’s got a hole at the side (SB 14;0) 34. She hasn’t seen that she’s dropped…she’s dropped the apples (SB 14;0) 35. She sometimes buy stuff and then paint it what haven’t got coat of paint on it (RJ 11;11) 36. He been tied on (AZ12 13;0) Contexts where adults would use a third person singular present form of the tense auxiliary DO 37. He don’t know (JW 10;3) 38. He don’t get hungry (JW 10;03) 39. What, when he don’t go to work? (JW 10;03) 40. And the bus don’t take no notice (AZ11 10;3) 41. And he don’t know how to (RJ 10;11) 42. He don’t know how to put his brakes on (AZ12 11;0) To what extent do these examples data bear out CBG’s claim (in the quotation in question 5) about how their subjects performed on marking agreement on auxiliaries in 3.Sg.present contexts? What is the significance of the fact that in many varieties of spoken English, don’t is used with all types of subject including third-person-singular subjects (as in the classic pop-song lament He don’t love me no more)? §5.8 On the generality of CBG’s findings about German Rice, Noll and Grimm (1997) report on two sets of spontaneous speech samples collected from 8 Germanspeaking SLI children in the age range 4;0-4;8 (the second sample collected a year after the first). They claim that the German children in their study showed 88% correct use of the 3Sg agreement marker -t at time TI and 100% at T2100, and 71% correct use of the 2Sg agreement suffix -st at time T1101 and 100% at T2. They also report that the children overall102 also showed 97% correct use of overt forms of sein ‘be’103. To what extent do Rice et al’s findings support the claims made by CBG about German SLI children? §5.9 On scoring procedures There are two different ways of scoring a child’s percent correct use of an agreement-marking item such as the third person singular present tense -s affix in English. One is to ask: How often does the child use -s in obligatory contexts (i.e. contexts where adults would use -s)? Another is to ask: When the child uses -s, how often does the child use it with an appropriate kind of (third person singular) subject? Rice, Noll and Grimm claim that the German children in their study scored 97% correct use of sein ‘be’, basing this figure on the fact that when the children used sein ‘be’ (rather than omitting it) they correctly inflected it in 97% (226/233) of the contexts in which it occurred. However, excluded from this score were 61 cases where sein ‘be’ was omitted. What methodological issue is raised by their 97% correct score? §5.10 Overall verdict What is your overall verdict on the strengths and weaknesses of CBG’s Agreement Deficit hypothesis? 100 T1 is the time when the first spontaneous speech samples were collected, and T2 the time (a year later) when the second were collected. 101 All their errors involved use of -t in contexts where -st is required. Since SLI children have phonological production problems (e.g. with fricatives like |s| and with consonant clusters like |st|), the use of -t in place of -st may well be a phonological rather than a grammatical error, as Rice, Noll and Grimm (1997, p.275) point out. 102 I.e. aggregating the figures from T1 and T2. 103 I.e. when the children used sein ‘be’ (rather than omitting it) they correctly inflected it in 98% (226/233) of the contexts in which it occurred. Excluded from this score are 61 cases where sein ‘be’ was omitted. 38 6. The Agreement-and-Tense-Omission (ATOM) account of SLI Key article Wexler K, Schütze C & Rice M (1998) ‘Subject case in children with SLI and unaffected controls: Evidence for the Agr/Tns Omission Model’, Language Acquisition 7: 317-344 OUTLINE OF WEXLER, SCHÜTZE AND RICE’S PAPER In their 1998 paper, Ken Wexler, Carson Schütze and Mabel Rice (henceforth WSR) argue that SLI involves a syntactic feature deficit which leads affected children to sometimes omit tense and agreement features in obligatory contexts: they refer to the model they propose as ATOM (= Agreement & Tense Omission Model). They argue that the case-marking of subjects as nominative or accusative by SLI children directly correlates with whether or not they mark agreement on verbs104. The Extended Optional Infinitives Model of SLI In research into normally developing/ND children, Ken Wexler (1994) argued that TD children go through a protracted stage (which generally lasts until around their 4th birthday) during which they alternate between producing finite verbs105 and bare infinitives106 in contexts where adults require finite verb forms: for obvious reasons, Wexler refers to this as the Optional Infinitives/OI stage. So, for example, in a past tense context a (tearful) child at the OI stage (when asked why she is crying) might say either Daddy ate my ice-cream or Daddy eat my ice-cream, alternating between the finite verb form ate and the bare infinitive form eat. Wexler also observed that during the OI stage, children tend to omit auxiliaries and copula BE in finite contexts, saying e.g. Daddy snoring rather than Daddy’s snoring, Daddy naughty rather than Daddy’s naughty, Daddy gone rather than Daddy’s gone, and Daddy no like cabbage rather than Daddy doesn’t like cabbage. The greater generalisation would appear to be that during the OI stage, TD children alternate between producing finite and nonfinite clauses in finite contexts107. In collaborative work, Ken Wexler and Mabel Rice (in conjunction with other researchers) have argued that SLI children go through an Extended Optional Infinitives/EOI stage which typically lasts until they are 7 or 8 years of age: see e.g. Rice, Wexler and Cleave (1995), Rice and Wexler (1996), and Rice, Wexler and Herschberger (1998). In early work, Wexler (1994) argued that Optional Infinitive structures (e.g. Daddy want one) result from SLI children having a Tense Deficit in the sense that in contexts where adults mark (auxiliary or main) verbs for present or past tense, SLI children sometimes mark tense but also sometimes leave verbs underspecified for tense (so that the verb want in Daddy want one surfaces in the tenseless infinitive form want rather than the present tense form wants or the past tense form wanted – the use of the infinitive form want representing a tense-omission error under Wexler’s assumptions). In later collaborative work between Ken Wexler and Carson Schütze (Schütze and Wexler 1996), it was argued that optional infinitives can arise as a result of either tense or agreement features (or both) being underspecified (i.e. omitted) – and this is the origin of the ATOM (Agreement/Tense Omission Model) outlined by WSR. 104 Throughout, I shall use the term verb to subsume both auxiliaries and main verbs. A technical complication which I shall set aside is that within the theoretical framework which WSR adopt, tense and agreement are taken to be properties of an abstract functor (traditionally labelled T/INFL). A slightly revised model appears in Wexler (2003) – though I have not included this here since it is technical and says little new about case and agreement. 105 I.e. verbs inflected for tense/agreement, such as am/was/enjoyed/saw etc. 106 A bare infinitive form is an infinitival verb-form like say/find/help/play etc. used without the infinitive particle to. The infinitival status of the verb-form is clearer in languages in which infinitives carry an overt inflection. For example, French and German children at the OI stage produce verbs carrying an overt infinitive inflection in finite contexts, giving rise to structures such as Fermer yeux Daniel ‘Close.Inf eyes Daniel’ or Thorsten Caesar haben ‘Thorsten Caesar have.Inf’ (where Inf is an infinitival suffix, and Caesar is the name of a doll). 107 I.e. They alternate between producing clauses which do or don’t contain a verb inflected for tense/agreement in contexts where adults require a clause containing a verb inflected for tense/agreement. 39 Accounting for verb morphology within the ATOM model WSR maintain that in finite contexts in adult English, verbs obligatorily carry person, number and tense features (the value of their person and number features being determined by agreement with their subject). So, in sentences like those in (1) below, the italicised verb forms will carry the parenthesised features: (1)(a) (b) (c) (d) Daddy plays with me [plays = present-tense, third-person, singular-number] Mummy and Daddy play with me [play = present-tense, third-person, plural-number] Daddy played with me [played = past-tense, third-person, singular-number] Mummy and Daddy played with me [played = past-tense, third-person, plural-number] WSR posit that the relevant regular verb inflections in English108 encode the following features: (2)(a) (b) (c) -s = [present-tense, third-person, singular-number] -d = [past-tense] -ø = [any other set of features] Informally, (2b) can be regarded as saying ‘If a regular verb carries the feature [past-tense], then (irrespective of whether or not it also carries other features like person and number), it will have the suffix -d added to its stem’. Let’s look at how we can account for the italicised verb forms in (1) in terms of the assumptions made in (2). In (1a), suppose that the syntax tells us we require the third person singular present tense form of the verb PLAY. We then search through the list of affixes in (2) in order to find the affix which provides the best match for the required set of features (and involves no mismatch). Since -s in (2a) is a perfect match, the affix -s is added to the stem play- to form plays, deriving (1a) Daddy plays with me. In (1b), suppose the syntax tells us that we require the third person plural present-tense form of PLAY. We again search through the list of affixes in (2) in order to find the affix which provides the best match for the required set of features (and involves no mismatch). The affix -s in (2a) will not do, since using it would involve a mismatch between the plural number required by the syntax and the singular number encoded by -s. Nor will the affix -d in (2b) do, since its use would involve a mismatch between the present tense required by the syntax and the past tense encoded by -d. Accordingly, the inflection -ø in (2c) is used by default (i.e. as a last resort, because the other two are not appropriate choices), since the use of -ø involves no mismatch by virtue of being able to encode any other set of features. This results in the null affix -ø being added to the stem play-, deriving Daddy and Mummy play-ø109 with me. In (1c), suppose the syntax tells us that we require the third person singular past tense form of PLAY. We search through the list of affixes in (2) in order to find the affix which best matches (and does not mismatch) the set of features carried by the verb PLAY. The -s affix will not do, because of the mismatch between the past tense feature specified in the syntax and the present tense feature specified in the entry for -s in (2a). This time, the best match is -d, since the entry for -d in (2b) contains a [past-tense] feature which matches the [past-tense] feature required by the syntax, but no further features (so that there is no mismatch110 with the person/number features of the required form). Accordingly, the affix -(e)d is added to the stem play-, deriving Daddy and Mummy play-ed with me. Essentially the same will be true in (1d), where once again the [past-tense] feature of the affix -d in (2d) provides the best match for the features required by the syntax in (1d). 108 They exclude (perfect/passive) participle uses of -d from their discussion, as well as the progressive participle and gerund affix -ing. Note that -d and -s are preceded by e in the spelling (and hence surface as -ed/-es) when added to certain types of stem, but this is a question of detail which I overlook here. 109 WSR assume that the verb in such cases carries a null affix. But (if you prefer) you can alternatively think of -ø in (2c) as meaning ‘Don’t add any affix at all to the verb’. 110 WSR posit that all of the features of an affix must be present in the syntactic representation for that affix to be used, but not all the features in a syntactic representation must be carried by an affix in order for the affix to be used. 40 Infinitives in finite contexts111 in the ATOM model WSR argue that the bare infinitives which children sometimes produce in finite contexts come about when the verb is underspecified for (i.e. lacks) tense and/or agreement features. Consider, for example, what happens if the child omits one or more of the [bracketed] features carried by the italicised verb in a structure like (3) below, repeated from (1a) above: (3) Daddy plays with me [plays = present-tense, third-person, singular-number] For example, if the child leaves the [present-tense] feature unspecified (perhaps treating tense as implicit112), the child’s syntactic structure will carry the features shown in (4) below: (4) Daddy play with me [play = third-person, singular-number] If (as WSR assume) children’s affixes generally encode the same set of features as their adult counterparts in (2) above, the child will search through the set of affixes in (2) to find the one which provides the best match and no mismatch. However, the affix -s cannot be used here, since the entry for -s in (2a) says that it can only be used where the syntax contains the feature [present-tense]; yet the (underspecified) syntactic structure in (4) contains no tense feature of any kind on the verb. For the same reason, the affix -d cannot be used either, since this encodes past tense and (4) contains no tense feature. Consequently, the null affix -ø in (1c) is used by default, and since it can be used to spell out ‘any other set of features’ on a verb, there is no feature-mismatch here. Accordingly the bare form play-ø is used in (4). Now let’s make the alternative assumption that the child’s counterpart of (3) is specified for present tense, but underspecified in respect of (person and number) agreement features, as shown informally below: (5) Daddy play with me [play = present-tense] The child will then search through the affixes in (2) to find the best match for the [present-tense] feature required by the syntax in (5). The affix -s will not, however, provide a good match, since the entry for -s in (2a) says that it can only be used where the verb also carries the features [third-person, singularnumber], and yet the underspecified verb play in (5) carries only the feature [present-tense]. Nor is the affix -d suitable, since this encodes past tense, and (5) tells us that we’re looking for a present-tense affix. Consequently, the affix -ø is used by default, resulting in the bare verb form play-ø (which is bare in the sense that it does not contain any overt affix)113. What our discussion here highlights is that (within the ATOM model) a bare verb form like play in a finite context in which adults require an inflected form like plays or played comes about by virtue of the verb being underspecified for its tense and/or agreement features – e.g. if the verb is underspecified for tense as in (4), or for agreement as in (5)114. A finite context is a context where an adult would use a finite (auxiliary or main) verb – i.e. one marked for tense and agreement. 112 E.g. perhaps assuming that it can be inferred from the context. So, for example, if a child replies to an adult present-tense question like ‘What does Daddy do when he comes home?’ the child might treat tense as something which can be inferred from the context (tense being seen, in some informal sense, as ‘given’ information – given by the use of the present-tense auxiliary does by the person asking the question), and hence say ‘Daddy play with me’, where play is not inflected for tense. 113 A further possibility which I won’t go into here is that Daddy play with me can also arise if the verb is underspecified for both tense and agreement. A possibility which WSR do not discuss is that a verb may be underspecified for one of its two (person and number) agreement features but not the other, resulting in partial agreement (in person but not number, or conversely in number but not person) between subject and verb. 114 More generally, a verb in a finite context will surface as an uninflected bare (infinitive) form if the verb is underspecified for any one or more of its person/number/tense features. 111 41 Auxiliary omission in finite contexts in the ATOM model As noted earlier, both TD and SLI children frequently omit the auxiliaries BE/HAVE/DO in finite contexts, hence producing auxilariless sentences such as: (6)(a) (b) (c) Daddy snoring/Daddy naughty (omission of is) Daddy gone out (omission of has) Daddy not like cabbage (omission of does) WSR posit that the function of such auxiliaries is to encode tense and agreement properties. They further assume that (just like main verbs) auxiliaries can optionally be underspecified for tense and/or agreement in finite contexts in child grammars, and that when HAVE/BE/DO are underspecified for one or more of their tense/agreement features, they are given a null phonetic spellout (i.e. so are ‘silent’115). So, in an adult sentence such as Daddy is snoring, the auxiliary BE will be fully specified for tense and agreement features, as in (7) below; (7) Daddy BE snoring [BE = present-tense, third-person, singular-number] Accordingly, the auxiliary BE will be spelled out in the corresponding 3Sg present tense form is. But suppose that a child marks the auxiliary BE for agreement but not for tense, as in (8) below: (8) Daddy BE snoring [BE = third-person, singular-number] In such a case, the (tense-) underspecified auxiliary BE will be given a null spellout, so that the resulting sentence is Daddy ø snoring, where ø is a null exponent of BE. Likewise, if the child specifies the auxiliary for tense but not agreement as in (9) below: (9) Daddy BE snoring [BE = present-tense] the (agreement-) underspecified auxiliary BE will again be given a null spellout, so deriving Daddy ø snoring. In other words, an auxiliary-drop sentence like Daddy snoring will result whenever BE/HAVE/DO is underspecified in respect of (i.e. lacks) one or more of its person/number/tense features116. Although (overt forms of) the non-modal auxiliaries BE/HAVE/DO encode both tense and agreement features, WSR posit that modal auxiliaries always encode tense, since they inflect for present/past tense (cf. pairs such as will/would, shall/should, can/could, may/might), and never carry the third person singular agreement inflection -s. So, the lexical entry for CAN will say that it is spelled out as follows117: (10) 115 CAN = can if [present-tense] could if [past-tense] A number of morphemes can have a null spellout in particular contexts in adult English. For example, possessive ’s has a null spellout when added to a noun ending in plural -s, as in the soldiers’ barracks. In colloquial English, have and are can have a null spellout in questions like Where you been? or What you doing?, perhaps as a result of more general phonological reduction processes (involving schwa-deletion). It may well be that auxiliaries are given a null spellout by children (by default) when their lexicon contains no auxiliary form which can match the features required in the syntax. 116 This is not intrinsically implausible, since BE can have a null spellout in certain structures in adult English. For example, in the dialogue below, speaker B can either spell out BE overtly, or not: A: You shouldn’t be rude about Queenie, like you were yesterday. B: Me be rude about the old bag? No way! Me rude about the old bag? No way! 117 (10) can be thought of as meaning ‘The word CAN is spelled out as the form can if it carries a present-tense feature (irrespective of whether or not it also carries other features such as person and number), and is spelled out as could if it carries a past tense feature (irrespective of whether or not it also carries other features like person and number)’. Recall that WSR assume that auxiliaries in finite contexts in adult English always carry not only a present or past tense feature, but also person and number agreement features. But if an SLI child has the same lexical entry (10) for CAN as adults (in accordance with what WSR assume), the child will be able to use can not only when he marks the auxiliary for both tense and agreement, but also when he marks it only for tense (omitting person/number agreement features). This assumption turns out to have important consequences for how the child case-marks the subject of can – as you will see shortly. 42 Case-marking in the ATOM model Noun and pronoun expressions in adult English inflect for case. English is traditionally said to have three cases, namely nominative, accusative (or objective), and genitive. Some pronouns have separate weak and strong genitive forms, a weak genitive form like my being used when modifying a following noun expression (as in my new car, where my modifies the noun expression new car), and a strong genitive form like mine being used in other structures (e.g. in sentences like This is mine or Mine is bigger than yours). The way in which the various case forms of personal pronouns are spelled out in English is shown in the table below (repeated from chapter 1): (11) Pronoun 1.SG 1.PL 2.SG/PL 3.M.SG 3.F.SG 3.N.SG 3.PL How case is spelled out on personal pronouns in adult English Spellout I if nominative, mine if strong genitive, my if weak genitive, me otherwise we if nominative, ours if strong genitive, our if weak genitive, us otherwise yours if strong genitive, your if weak genitive, you otherwise he if nominative, his if genitive, him otherwise she if nominative, hers if strong genitive, her otherwise its if genitive, it otherwise they if nominative, theirs if strong genitive, their if weak genitive, them otherwise (1/2/3 denote 1st/2nd/3rd person; SG = singular; PL = plural; M = masculine; F = feminine; N = neuter.) In contrast to personal pronouns, noun expressions have a common nominative-accusative form and a distinct genitive ’s form (cf. nominative-accusative George/the president and genitive George’s/the president’s). The case carried by a pronoun or noun expression depends on its position within the structure containing it. Below, I present a simplified version of the assumptions which WSR make about case assignment in English: (12) Case Assignment (simplified) A pronoun or noun expression is assigned (i) nominative case if the subject of an agreeing verb118 (ii) genitive case if a possessor119 (iii) accusative case otherwise Since otherwise forms are technically referred to as default forms, it can be said that accusative is the default case in English120. To see how (12) works, consider the case-marking of the italicised pronouns in the following sentence: (13) He has been fooling around, so I can see why she got upset The auxiliary has here is a third person singular (present tense) form which agrees in person and number with its (third person singular) subject he, so that he carries nominative case by virtue of agreeing with has, in accordance with (12i). Since WSR hypothesise that all verbs marked for tense in adult English agree in person and number with their subject, it follows from their assumptions that the present-tense auxiliary can agrees in person and number with its (its first person singular subject I), so that can (as used 118 In the context of the discussion of agreement here, the term verb should be taken to include both auxiliary verbs and main verbs: an agreeing verb is one which agrees with its subject in person and number. In more abstract syntactic analyses of clause structure in which T/INFL is said to be the locus of tense/agreement features, an expression is assigned nominative case via agreement in person and number with T/INFL, and the agreement features attach to the auxiliary in T/INFL if there is one, and (if not) are otherwise lowered onto the main verb. The idea that nominative case is assigned via person/number agreement with a verb dates back to work by Rouveret (1980) and Raposo (1987) on tenseless agreement-inflected infinitives with nominative subjects in Portuguese. 119 WSR have nothing much to say about genitive case, or how SLI children case-mark possessors. 120 However, note that in some other languages (e.g. German or Arabic), nominative appears to be the default case. See Schütze (2001) for a technical discussion of the notion of default case. 43 here) is a first-person-singular present-tense form: by virtue of agreeing in person and number with can, the subject I is assigned nominative case in accordance with (12i)121. Given WSR’s assumption that all present/past tense verbs in adult English agree in person and number with their subjects122, it follows that the verb got (as used here) carries the features [past-tense, third-person, singular-number] via agreement with its third person singular subject she, and conversely that she is assigned nominative case in accordance with (12i) by virtue of agreeing in person and number with got. Given the impoverished nature of verb morphology in present-day English, the agreement properties of past tense verbs are no longer directly visible (except on the forms was/were). Now consider the case-marking of the italicised pronouns in: (14) Please don’t report me to her! Here, me is the object/complement of the verb report: by virtue of not being the subject of an agreeing verb, and not being a possessor, me is assigned accusative case in accordance with (12iii). Likewise, her is the object/complement of the preposition to, and so is also assigned accusative case in accordance with (12iii). The Case Spellout List in (11) tells us how the various different case-forms of pronouns are spelled out and includes the following entry: (15) 3FSG = she if nominative, hers if strong genitive, her otherwise What the ‘her otherwise’ condition in (11/15) means that a third person singular feminine pronoun gets spelled out as her unless a nominative or strong genitive form is required: in other words, her is used when we need a weak genitive form (as in her dress) or an accusative form (as in Help her!). More generally, when accusative forms are required, they are always spelled out as the otherwise form. Next, consider the case-marking of the italicised pronouns in: (16) My computer isn’t as powerful as yours By virtue of being possessors (in the sense that my in the expression my computer denotes the person who possesses the computer), the pronouns my and yours are assigned genitive case in accordance with (12ii). Since my is immediately followed by a noun expression (namely the noun computer), it is spelled out as the weak genitive form my (rather than the strong form mine), whereas since yours isn’t followed by a noun expression, it is spelled out as the strong genitive form yours (rather than the weak genitive my). Finally, consider the italicised pronouns in the (self-obsessed me-me-me) three-way conversation below: (17) SPEAKER A: Me, I reckon you’ll be a pop star one day SPEAKER B: Me be a pop star? No way! Who’d wanna SPEAKER C: Me! be a pop star, anyway? The pronoun me in (17A) serves the function of being the topic of the overall sentence, and the clause which follows it (namely I reckon you’ll be a pop star one day) is referred to as the comment. In (17B), ME is the subject of what is known as a ‘Mad magazine sentence’ (because it resembles a sentence which appeared on the front cover of the American magazine Mad). In (17c), Me is a sentence fragment – i.e. an expression which isn’t a complete sentence. An interesting question which arises in relation to the three uses of the italicised pronoun in (17) is how it comes to be spelled out as the accusative form me. The answer is that since me is neither the subject of an agreeing verb nor a possessor, it gets assigned accusative case by default – i.e. via the otherwise condition in (12iii). 121 In earlier varieties of English, CAN overtly inflected for agreement in forms like thou canst. However, its agreement inflections have been lost in the course of the historical evolution of the language. The counterpart of CAN in languages like Italian overtly inflects for person/number agreement with its subject, as we see from forms like posso/puoi/può/possiamo/potete/possono = ‘can.1SG/2SG/3SG/1PL/2PL/3PL’. 122 This agreement is more directly visible in languages like Spanish/Italian with a much richer overt subject-verb agreement morphology than English. 44 Predictions of the ATOM model about case marking in SLI children’s grammars The analysis of case-marking outlined in the previous section, taken together with the core assumption of the ATOM model that (auxiliary and main) verbs can be underspecified for (i.e. lack) tense and/or agreement features in finite contexts makes a number of specific predictions about the patterns of casemarking that we will find in the grammars of SLI children at the EOI stage (and indeed in TD children at the OI stage) children. Predictions about the case-marking of subjects and objects are outlined below123. Predictions about the case-marking of objects by SLI/TD children appear straightforward enough; the object of a verb or preposition would be expected to be assigned accusative case by (12iii), and we should therefore expect that SLI (and indeed TD) children would make no case errors with objects. Predictions about the case-marking of subjects are rather more complex, because of the possibility that the associated verb may (or may not) be underspecified for tense and/or agreement. There are three different types of sentence which we need to consider here. A straightforward case are sentences containing a main verb or a non-modal auxiliary like HAVE/BE/DO which is overtly inflected both for tense and for agreement in person and number with its subject (e.g. as in Daddy snores, Daddy is snoring): such sentences will be predicted always to have nominative subjects in accordance with (12i) because the verb agrees with the subject (so that we expect to find He snores, He is snoring). Less straightforward are modal auxilaries and past tense main verbs124. Both encode tense (e.g. can is a present-tense modal auxiliary verb, could is a past tense modal auxiliary verb, and went is a past tense main verb), but if SLI children at the Extended Optional Infinitives/EOI stage optionally mark agreement on (auxiliary or main) verbs in finite contexts, modals and past tense verbs may either be specified for agreement or not. If a modal or past tense verb is specified for agreement in person and number with its subject, it is predicted to have a nominative subject by (12i) (as in He can swim, He could help and He went out). But if a modal or past tense verb is underspecified for agreement, its subject will assigned accusative case by default, in accordance with (12iii) (as in Him can swim, Him could help and Him went out). Overall, then, SLI children at the EOI stage are predicted to alternate between using nominative and accusative subjects for modals and past tense verbs. Finally, let’s consider structures involving bare verbs (e.g. Daddy play with me) and ‘missing’ auxiliaries (e.g. Daddy working, Daddy gone out, Daddy naughty). As we saw earlier, within the ATOM model there are three ways in which such structures can arise, namely: (i) if the verb/auxiliary is specified for tense but not agreement; (ii) if it is specified for agreement but not tense; or (iii) if it is specified for neither tense nor agreement. If the (auxiliary/main) verb is specified for (person and number) agreement but not tense, the subject will be predicted to be nominative by (12i) (yielding e.g. He play with me, He working, He gone out, He naughty). If the (auxiliary/main) verb is specified for tense but not agreement, the subject will be accusative by (12iii): likewise, if the (auxiliary/main) verb is specified for neither tense nor agreement, the subject is again predicted to be accusative by (12iii); in both cases, we expect to find children producing structures such as Him play with me, Him working, Him gone out, and Him naughty (where the subject him is a default form). Since two of the three possibilities discussed here yield accusative subjects, we might expect accusative subjects to be more frequent than nominative subjects in such structures (for any SLI child in the EOI period who leaves tense underspecified roughly as frequently as agreement)125. Overall, WSR classify the structures which SLI children at the EOI stage would be expected to produce in contexts where adults use a finite clause (i.e. a clause containing an auxiliary/main verb marked for tense and agreement) into the three main types indicated below: WSR don’t discuss how SLI children at the EOI stage (and TD children at the OI stage) case-mark possessors. It makes no difference for case-marking purposes whether the past tense verb is regular or irregular. 125 Note that WSR make no specific claims about whether children omit agreement features more or less frequently than they omit tense features. 123 124 45 (18)(I) Structures containing an (auxiliary/main) verb inflected for both tense and agreement (predicted to have nominative subjects: e.g. He snores, He is snoring). Since such sentences overtly mark agreement, WSR classify them as agreeing sentences. (II) Modal/past tense structures in which tense is marked, but agreement may or may not be marked (predicted to have either nominative or default subjects: e.g. He/Him went out, He/Him can swim). Since we can’t directly tell from the impoverished morphology of such verb forms whether agreement is marked or not, WSR classify such sentences as ambiguous. (III) Bare verb/missing auxiliary structures which are ambiguous in respect of whether they are (i) specified for agreement but not tense, (ii) specified for tense but not agreement, or (iii) specified for neither tense nor agreement: (i) would yield nominative subjects (e.g. He snore, He snoring), and (ii/iii) accusative subjects (e.g. Him snore, Him snoring). Since such sentences contain no verb/auxiliary overtly inflected for agreement, WSR call them uninflected sentences. WSR predict that accusative subjects will be more frequent in uninflected than ambiguous structures. Thus, they write (1998, p.303): ‘We classified utterances into agreeing, ambiguous… and uninflected. Agreeing forms include main verbs with -s (e.g. likes), and agreeing auxiliaries and copulas (e.g. is/are). Ambiguous forms include past-tense verbs (e.g. liked) and modals (e.g. can). Uninflected forms include main verbs missing -s (e.g. *Mary like126), omitted auxiliaries and copulas (e.g. *Mary going, *Mary pretty), and the rare instances of uninflected auxiliaries (e.g. *Mary be). This category also included main verbs that were intended as past tense semantically but were not marked as such’. Methodology of WSR’s study The data which WSR present in their paper are based on two sets of spontaneous speech samples and experimental data (collected at 6 month intervals) from 23 SLI children with a mean age of 4;9 in round 1 and 5;5 in round 2127, and 20 MLU-matched TD children with a mean age of 3;0 at round 1 and 3;7 at round 2. The experimental task was designed to elicit sentences with third person singular pronoun subjects (to check both case and agreement marking). Case-marking in WSR’s study WSR report that (as expected under the ATOM model) both the SLI and the TD children virtually always correctly case-mark pronouns in accusative contexts. Relevant data are given in (15) below: Frequency of accusative pronouns128 in accusative contexts Group Round 1 SLI children 203/204 (99.5%) MLU-matched TD children 166/166 (100%) (19) Round 2 244/245 (99.6%) 222/222 (100%) By contrast, both the TD and SLI children make errors with the case-marking of subjects in nominative contexts (i.e. in contexts where the corresponding adult sentence would have a nominative subject), as shown by the data in the table below: 126 The asterisk indicates that the relevant structures are ungrammatical in adult English. Rounds 1 and 2 denote the periods of time when the earlier/later sets of data were collected. 128 The data here relate only to pronouns which show an overt nominative/accusative contrast, namely I/me, we/us, he/him, she/her and they/them. WSR exclude you and it from this count on the grounds that they have a common nominative/accusative form (so it’s impossible to be sure whether you/it in a given sentence is nominative or accusative). 127 46 (20) Mean percent correct use of nominative he/she subjects in nominative contexts129 Group/Round Round 1 Round 2 Round 1 Round 2 Data type spontaneous spontaneous elicited elicited SLI children 57% 77% 56% 59% ND children 85% 83% 96% 86% Given the assumptions of the ATOM model (namely that TD children optionally leave tense and/or agreement underspecified until around their 4th birthday, and SLI children until around their 8th birthday, and that agreement-underspecification leads to errors in the case-marking of subjects), we should expect to find that both 5-year old SLI children and 3-year-old TD children will make case-marking errors with subjects in nominative contexts, but that the SLI children will make more errors than the TD children (since a 3-year old TD child is closer to the end of the EOI period than a 5-year old SLI child). These predictions would seem to be borne out by the data in (23). All but one of the case errors on subjects involved using an accusative subject in a context where adults would uses a nominative subject130. Relation between nominative case and agreement In principle, the ATOM model makes the prediction that sentences in which (person/number) agreement is marked will have nominative subjects, whereas sentences in which agreement is not marked will have accusative subjects. In terms of the classification in (21) above, WSR would predict that agreeing sentences have nominative subjects, ambiguous sentences (i.e. sentences containing modals or past tense verbs) should have either nominative or accusative subjects, and uninflected sentences (i.e. sentences with a bare verb or missing auxiliary) should likewise have either nominative or accusative subjects – though with accusative subjects occurring more frequently in uninflected than in ambiguous sentences, given their assumptions. WSR summarise the predictions of the ATOM model in the following terms (1998, p.333): ‘Agreeing verbs should show the fewest non-Nom131 subjects, in principle none at all. Ambiguous verbs should show some non-Nom subjects, more than agreeing verbs, and uninflected verbs should show the highest proportion of non-Nom subjects.’ Adjusting for lexical gaps WSR focus mainly on sentences with 3Sg M/F personal pronoun subjects, since regular verbs only inflect for agreement in present-tense 3Sg forms, and since 3Sg M/F personal pronouns overtly inflect for the nominative/accusative case contrast (cf. he/him and she/her132). However, the possibility that the children may not have acquired the full set of pronouns found in adult English also needs to be controlled for. For example, the pronoun she is often acquired relatively late133 by children: children who have not yet acquired she have a lexical gap (i.e. have a gap in the set of pronoun forms listed in their lexicon relative to the set of pronouns forms found in the adult lexicon). They often extend some other pronoun (typically he or her) to take over the role played by she in the adult system: so, for example, a child who has not yet acquired she might extend her from use as an accusative/genitive pronoun to additional use as a nominative pronoun, hence using her in nominative contexts, as in Her’s naughty. For such a child, her would therefore have a different status from its adult counterpart; whereas a 3FSg (third person feminine 129 This table includes only third person singular masculine/feminine pronouns (he/him/his/her). WSR report one occurrence of a genitive his subject in their spontaneous speech data. However, as has often been noted, it can sometimes to be hard for transcribers to determine whether a child says e.g. His sleep or He’s sleep (and indeed to determine whether this is the child’s counterpart of He’s asleep or He’s sleeping). Because genitive his subjects are virtually non-existent, WSR take her subjects to be accusative where they occur alongside she subjects, and not genitive. Of course, if the children used genitive subjects, we’d also expect to find forms like Daddy’s can do it where the subject Daddy surfaces in the genitive form Daddy’s: I assume these did not occur, since WSR do not mention them. 131 Non-nominative (i.e. apparent accusative/genitive forms). 132 They exclude the inanimate (neuter) pronoun it, because it has the same form in nominative (cf. It is difficult) and accusative (cf. Forget it!) contexts. 133 Perhaps because other 3Sg animate pronouns like he/him/his/her all begin with h-, making she irregular in respect of its onset (i.e. its initial consonant). 130 47 singular) pronoun would be spelled out as in (21a) below in adult English, for a child with a defective (she-less) pronoun paradigm, a 3FSg pronoun might be spelled out as in (21b): (21)(a) ADULT: 3FSg = she if nominative, hers if a strong genitive, her otherwise (b) CHILD: 3FSg = hers if a strong genitive, her otherwise Because of this, for a child with the impoverished (she-less) pronoun system in (21b), we cannot tell what case is carried by her subjects (in sentences like Her naughty, Her’s cheating, Her can do it etc.), since her (for such a child) could in principle be a nominative, genitive or accusative/default form. To avoid problems in determining the case properties of pronouns used by children with defective pronoun paradigms134, WSR decided to exclude pronoun forms which are ambiguous in the child’s grammar from their calculations. WSR’s results The figures which WSR arrive at for subject case-marking with third person singular animate (i.e. masculine/feminine) pronouns in spontaneous speech samples are shown in the table below: (22) Frequency of he/she subjects in nominative contexts in spontaneous speech samples Group Clause type Round 1 Round 2 SLI children agreeing 30/43 (70%) 25/29 (86%) SLI children ambiguous 15/31 (48%) 27/38 (71%) SLI children uninflected 28/129 (22%) 19/38 (50%) ND children agreeing 51/55 (93%) 39/50 (78%) ND children ambiguous 19/24 (79%) 23/30 (77%) ND children uninflected 40/58 (69%) 13/22 (59%) WSR’s conclusions WSR draw 7 main conclusions about case-marking from their study. Firstly, it is specifically the casemarking of subjects which causes problems for SLI and TD children alike, not (e.g.) the case-marking of objects. Secondly, SLI children make more frequent case-marking errors with subjects than MLUmatched TD children. Thirdly, the type of case-marking error SLI children make involves using an accusative form in contexts where adults require a nominative form. Fourthly, the case-marking of subjects (viz. whether subjects are spelled out as nominative or accusative forms) is determined by whether clauses contain an auxiliary/main verb135 which agrees in person and number with the subject or not. Fifthly, the overall characteristics of children’s verb morphology and pronoun case morphology follow from the ATOM model, in which children leave verbs underspecified for tense and/or agreement features in finite contexts, resulting in the production of Optional Infinitive/OI structures with accusative subjects. Sixthly, the OI period is far more extended in SLI children (lasting until around their 8th birthday) than in TD children (lasting until around their 4th birthday), so that a 3-year old TD child is closer to the end of the OI period than a 5-year old SLI child (and hence a 5-year-old SLI child could be expected to make more errors with verb morphology and subject case-marking than an MLU-matched 3-year old TD child). And finally, the ATOM model makes (limited) predictions about the relative frequency of case and tense/agreement errors made by children in different types of clause structure (e.g. with subject case-marking errors predicted to be most frequent with uninflected verbs, less frequent with ambiguous verbs, and least frequent with agreeing verbs)136. 134 I.e. children who have not acquired the full range of pronouns found in adult English. More precisely, an INFL/Agr constituent (a technical complication which I gloss over here). Recall that WSR assume that an auxiliary like BE/HAVE/DO will be invisible (= have a null spellout) if underspecified for tense, or agreement, or both. 136 However (as pointed out earlier), ATOM makes no specific claims about whether tense features are omitted more frequently than agreement features – or conversely. 135 48 WORKBOOK SECTION In many ways, WSR’s analysis replicates the findings of earlier work by Loeb and Leonard (1991), who likewise showed that SLI children make case-marking errors with subjects rather than objects, and hypothesised that these errors are the result of an agreement deficit (i.e. of verbs lacking subjectagreement features). However, WSR posit that SLI children additionally have a tense deficit in the sense that they sometimes also fail to mark tense on verbs in obligatory contexts. WSR’s main contribution to our understanding of SLI lies in their formulation of a specific developmental model – the ATOM model – which incorporates a principled model of tense/agreement morphology, and which provides a principled account of case-marking by SLI children in different types of clause structure. But does the ATOM model account for the full range of sentences types produced by SLI children (in particular, the types of case error they make), or are there some types or error not accounted for by ATOM – and if so, how can they be accounted for? These are the questions which the exercise material below is designed to help you answer. §6.1 Data from child D in the Leonard corpus Below are a selection of examples (from the Leonard files on the CHILDES data-base) of sentences with produced by a male child with SLI (identified only as D) at age 4;4. Discuss the case-marking of subject pronouns in these sentences, and say whether it conforms to the predictions made by ATOM or not. Identify sentences which appear to be problematic for the ATOM account, and see if you can suggest ways of dealing with them. 1 I’m strong 2 I’m trying kill him 3 I have Superman on tape 4 Where do I put this? 5 They’re jumping 6 They’re big 7 They’re shoes 8 Yeah, they do 9 I can’t do it 10 I don’t feel well 11 I don’t know what them are 12 Me don’t want those 13 Me don’t know how do it 14 I said I did all that 15 I gonna kill you 16 I been there 17 I in this 18 I not in that picture 19 Them mad at him 20 Them not plate 21 Them is big 22 Them is boys 23 Me’s right here 24 You’re wrong 25 You are gonna turn it? The Standard English/SE equivalent of sentences which differ from their SE counterparts are as follows: 2 I’m trying to kill him 11 I don’t know what they are 12 I don’t want those 13 I don’t know how to do it 15 I’m gonna kill you 16 I’ve been there 17 I’m in this 18 I’m not in that picture 19 They’re mad at him 20 They’re not plates 21 They’re big 22 They’re boys 23 I’m right here. In relation to sentences containing overt present tense forms of BE, assume that these are spelled out as follows: BEPRESENT = am if first person and singular, are if second person or plural, is otherwise Also consider (in addition to the possibilities envisaged by ATOM) the further possibility that SLI children may sometimes mark a verb for partial agreement with its subject (in either person or number), but that only a verb which agrees in both person and number with its subject has a nominative subject (other verbs having default accusative subjects): show how these assumptions would help you account for sentences containing I’m, me’s, they’re, them are and them is. §6.2 Data from child J in the Leonard corpus Below are all the examples (from the relevant file in the Leonard corpus on the CHILDES data-base) of sentences with 3MSg (third person masculine singular his/him/his) pronouns produced by a female child with SLI (identified only as J) at age 4;11. (Glosses or contextual information are provided in parentheses). Discuss the case-marking of italicised pronouns, and say whether it conforms to the predictions made by ATOM or not. Identify sentences which appear to be problematic for the ATOM model, and see if you can suggest a way of dealing with them. 3MSg pronouns in accusative contexts 1. How about him? 2. Him got him. 3. I dropped him. 4. You stand him upside down. 5. I want him. 6. Dress him. 7. I can’t get him out. 8. Gonna put him right here. 9. Yeah, that him. 10. Him (Occurred immediately after he had asked himself ‘Now what do I need?’) 49 3MSg pronouns in nominative contexts 11. Him is. 12. Him can be nice. 13. Him can ride way, way in the back. 14. Maybe him don’t fit in here. 15. Him want to now (‘He wants…’). 16. Him want to (‘He wants...’) 17. Him catch (= ‘He caught’). 18. Him jump off the chair (‘He jumped…’). 19. Him walk off the table (‘He walked…’). 20. Him got him (‘He got…’). 21. Him got little pig barn (‘He’s got…’). 22. Except him got green and I got red. (‘He’s got…I’ve got’) 23. Him walking like this (‘He’s walking…’). 24. Him driving (‘He’s driving’). 25. And him riding (‘He’s riding’). 26. Him riding the car (‘He’s riding…’). 27. Him climbing the tree (‘He’s climbing…’). 28. Him running fast and him walking slow (‘He’s…he’s’). 29. And him walking slow (‘He’s…’) 30. Him jumping on him car (‘He’s…. ) 31. Him gonna go to bed (‘He’s…). 32. Hope him gonna hit him butt (‘…he’s…’) 33. Him gonna sit down in there (‘He’s). 34. Him gonna go in here (‘He’s…’) 35. Him bad guy (= ‘He’s a bad guy’). 36. Him the driver (‘He’s…). 37. Him on the chair (‘He’s…’). 38. Him in bed asleep (‘He’s…’). 39. Him under him bed turn (‘He’s…’). 3MSg pronouns in genitive contexts 40. Spilled his water. 43. Comb him hair. 46. Him under him bed turn. 49. Hope him gonna hit him butt. 41. The dog chewing him bone. 44. Hay to him donkey. 47. Him jumping on him car. 50. Him car go. 42. Zip him jacket up. 45. How pig get in him thing? 48. Walking on him car. 51. The baby drop him bottle. §6.3 Looking at the behaviour of one of the children in WSR’s study The following are extracts from the transcript of one of the recordings of one SLI child included in WSR’s study. (The child was aged 4;6 at the time of the recording, and was subject number 19700128: I am grateful to Mabel Rice for providing me with a copy of the transcript.) Below, I have listed all the sentences with a third person masculine singular pronoun subject produced by the child in the transcript. 1. Him got away137 2. Him went up high stairs 3. Him did138 4. Him jump on light139 140 141 142 5. No, him jump 6. Him jump. 7. Him jump high 8. He eat it143 144 145 146 9. Him too big . 10. Him wild cat 11. Him a wild cat . 12. Him a wild cat 13. Now him high147 14. Now him back148 15. Him mad149 16. Him mad people150 151 152 17. Now him under table 18. Him right here my back 19. Him not hungry153. 20. Him up154 155 156 21. Him up there 22. Him upstairs 23. Now him up high157 24. Him walking street158 The interviewer responds ‘He got away?’ Produced after the interviewer said ‘Get off the table’. 139 This sentence was scored as an attempt at ‘He jumped on the light’. 140 Produced after the interviewer said ‘The cat didn’t jump up on there’. 141 The interviewer responds ‘He did. He jumped onto the ground’ 142 The interviewer responds ‘He jumped high’. 143 The interviewer responds ‘He ate it’ 144 Produced after the interviewer had said ‘Maybe Mommy can fit in there’. 145 The interviewer responds: ‘He’s a wild cat?’ In most of the sentences here, him/he refers to the cat being talked about. 146 The interviewer responds: ‘It’s a wild cat’. 147 Produced after the interviewer says ‘The cat’s going upstairs’. 148 The cat has come back after going upstairs. 149 The interviewer then asks ‘Why’s he mad?’ Him mad was also produced on 4 other occasions. 150 The interviewer then says ‘He is mad at the people’. 151 The interviewer then says ‘Oh, he’s under the table’. 152 This sentence was scored as an attempt as ‘He is right here behind my back’ 153 The interviewer responds ‘Oh, he’s not hungry’. 154 Produced after the child had previously said ‘This cat all tired’. 155 The interviewer responds ‘He’s upstairs’ 156 Talking about a rat. 157 Interviewer replies ‘Oh, he’s up really high’ 158 The interviewer then says: ‘He’s walking on the street?’ 137 138 50 25. Now him eating159 26. Now him going160 27. Him hiding my back161 28. Him going 162 29. Him looking out there 30. Him sitting down 31. Him be up there163 32. Now he’s low 33. No, him don’t like peanut164 34. Him scratch165 35. Yeah, him go in166 36. Him want to lie down 37. Him bites people167 38. Him scratches people The point of this exercise is to get you to look at which of the child’s utterances are in conformity with the predictions of ATOM, and which are not. What you might do is the following. (i) Look at the sentences 1-8 which the child appears to have produced in past tense contexts. Say what range of different structures you find, and what range of structures ATOM would predict to occur, and try to account for any discrepancy between predicted and occurring structures. More specifically, say whether (and if so how) ATOM could account for sentences like 1, 6 and 8, discussing any problems which arise. (ii) Look at the sentences 9-32 which occur in is contexts (i.e. in contexts where adults would use the verb is or its contracted counterpart ’s – e.g. Him too big corresponds to the adult form He’s too big). Say what range of different structures you find, and what range of structures ATOM would predict to occur, and try to account for any discrepancy between predicted and occurring structures. In addition, say whether (and if so how) ATOM could account for sentences like 30, 31 and 32, discussing any problems which arise. (iii) Look at the sentences in 33-38, which all seem to occur in third-person-singular present-tense contexts (the adult counterpart of 33 containing a 3Sg Present form of the auxiliary DO, and the adult counterpart of 34-38 containing a 3Sg Present main verb). Say what range of different structures you find, and what range of structures ATOM would predict to occur, and try to account for any discrepancy between predicted and occurring structures. In particular, say whether (and if so how) ATOM could account for sentences like 33, 34 and 37, discussing any problems which arise. (iv) On the basis of the assumptions made in the ATOM model, try and calculate how frequently the child marks tense and agreement. Compare the tense suppliance rate you arrive at with the agreement suppliance rate, and try to account for any differences you find between the two. §6.4 Overall verdict What is your overall verdict on the strengths and weaknesses of the ATOM model? To what extent could ATOM be said to be an explanatory model? The interviewer responds ‘Now he’s eating, OK’ Produced after the interviewer says ‘He’s all done?’ 161 The interviewer says ‘He’s hiding behind your back’. 162 The interviewer responds ‘Yeah, he’s looking out the window’ 163 Glossed in the transcript as an attempt at ‘He is up there’. 164 Produced after the interviewer says ‘This elephant likes peanuts’. Bear in mind that in many varieties of colloquial American English, don’t (like won’t) is used with any kind of subject, including a third person singular subject like he/she/Daddy – hence the fact that soulful/doleful American pop songs typically lament that ‘He don’t love me no more’ rather than that ‘He doesn’t love me any more’. 165 Produced just after the interviewer has said (about a cat) ‘Oh, he bites people’. 166 The interviewer responds by saying ‘Do wild cats go in houses?’ 167 Produced just after the interviewer said ‘I want to play with the kitty’. The same sentence was also produced on one other occasion. 159 160 51 7. The Dependency Deficit account of SLI Key article Van der Lely HKJ and Battell J (2003) ‘Wh-movement in children with grammatical SLI: A test of the RDDR hypothesis’, Language 79: 153-181 OUTLINE OF THE DEPENDENCY DEFICIT MODEL In work stretching back more than 10 years (See e.g. van der Lely, 1994, 1998, 2005; van der Lely & Stollwerck, 1997; van der Lely and Battell 2003), Heather van der Lely has developed a model of SLI which she terms the Representational Deficit for Dependency Relations Model (RDDR) – though it will hereafter be referred to more succinctly as the Dependency Deficit Model (DDM). The core assumption of DDM is that SLI children have problems in handling structure-dependent operations – i.e. grammatical operations which involve a structural dependency between two different constituents, such as agreement (e.g. of a verb with its subject), case-marking (e.g. of a subject by a verb) and movement (which involves one constituent attracting another to move next to it). Van der Lely and Battell (2003) argue that DDM gains empirical support from an elicited production study of the wh-questions produced by a group of ESLIs (i.e. English subjects with SLI). Below is an outline of key claims made in their paper. VAN DER LELY AND BATTEL’S STUDY Van der Lely and Battell (henceforth VB) report on a study of the production of wh-questions by a group of ESLI subjects with persistent problems in grammatical production and comprehension, but not in other areas of language development168. They claim that the SLI subjects in their study fail to master the syntax of the two types of movement operation involved in wh-questions (= preposing a wh-expression and preposing an auxiliary), and argue that this is the result of difficulties they have in representing syntactic dependencies between constituents. Since following the argumentation in their paper requires an understanding of the assumptions they make about the syntax of adult wh-questions, let’s begin by taking a look at the syntax of wh-questions in adult English. Wh-questions in adult English Before we look specifically at wh-questions, let’s first outline some basic assumptions made about the structure of interrogative clauses (i.e. question structures). To make our discussion more concrete, consider the structure of the sentence produced by speaker B in the following dialogue: (1) SPEAKER A: What do you want to know? SPEAKER B: If Ralf can see her In work in syntax over the past 30 years (dating back to Chomsky 1986), it would be assumed that speaker B’s sentence is derived (i.e. formed) as follows. The verb see is merged (i.e. combined) with its (direct object) complement her to form the VP/verb phrase see her. The (present-tense) T/tense-auxiliary can is merged with the resulting VP see her and with its subject Ralf to form the TP (i.e. tense phrase – a term used for an expression containing a present- or past-tense auxiliary) Ralf can see her. This TP is in turn merged with the interrogative C/complementiser (a term used to denote a clause-introducing particle) if to form the CP/complementiser phrase If Ralf can see her (where if serves the function of marking the relevant clause as a yes-no question). Given these assumptions, speaker B’s sentence in (1) will have the CP+TP+VP structure shown below: (2) [CP [C if] [TP Ralf [T can] [VP [V see] her]]] But now suppose that instead of saying If Ralf can see her, speaker B had instead given the reply below: (3) SPEAKER A: What do you want to know? SPEAKER B: Can Ralf see her? They refer to the relevant form of SLI as G-SLI – i.e. a form of SLI which is characterised by a specifically grammatical impairment. 168 52 Let’s suppose (in line with much thinking in current work in syntax) that all questions have a CP+TP+VP structure, and that the derivation of Can Ralf see her? starts out in the same way as for If Ralf can see her. If so, the verb see is merged with its complement her to form the VP/verb phrase see her, and the T/tenseauxiliary can is then merged with this VP and with its subject Ralf to form the TP/tense phrase Ralf can see her. As in the case of (2), the next stage in the derivation of the sentence is for this TP to be merged with an interrogative C/complementiser: but this time, instead of containing if, the relevant interrogative complementiser is null (i.e. ‘silent’), because if is only used in complement clause questions, not in mainclause questions169. Merging the null complementiser with the TP we have already formed will derive the structure shown in (4) below: (4) [CP [C ø] [TP Ralf [T can] [VP [V see] her]]] However, the C constituent in a main-clause question (has a tense feature which) attracts the head T constituent can of the TP Ralf can see her to move from the T position into the C position (an operation traditionally called auxiliary inversion, but known in more recent work as T-to-C movement). The relevant (T-to-C) movement operation is represented by the arrow in (5) below, with strikethrough on can indicating the position occupied by can before it moved from T to C: (5) [CP [C Can] [TP Ralf [T can] [VP [V see] her]]] In the light of our discussion of yes-no question structures like (5), let’s now turn to consider the structure of wh-questions such as the following (adapted from VB p.157): (6) Who can Ralf see? This is similar in part to Can Ralf see her – but with the exception that the (direct object) complement of the verb see is the interrogative wh-pronoun who rather than her. More specifically, the derivation of the sentence proceeds as follows. The V/verb see is merged with its complement who to form the VP/verb phrase see who. The T/tense-auxiliary can is then merged with the VP see who and with its subject Ralf to form the TP/tense phrase Ralf can see who. This is then merged with a null interrogative C constituent, forming the CP shown in (7) below: (7) [CP [C ø] [TP Ralf [T can] [VP [V see] her]]] As in main-clause yes-no questions, the null C constituent at the beginning of the clause attracts the T-constituent (i.e. present-tense auxiliary) can to move from T into C. But since this is a wh-question, C also attracts the wh-word who to move out of its original position into a new position at the front of the overall CP (in front of the inverted auxiliary) – this second type of movement operation being known as wh-movement. The effect of these two movement operations (T-to-C movement and wh-movement) is indicated by the arrows below (where can and who indicate the original positions occupied by these two words before they underwent movement to the italicised positions): (8) [CP Who [C can] [TP Ralf [T can] [VP [V see] who]]] To introduce some technical terminology at this point, the inverted auxiliary can moves into the head C position in CP, while the preposed wh-word who moves into the specifier position within CP (the 169 In traditional grammar, main-clause questions are termed direct questions, and complement-clause questions are termed indirect questions. The structure if Ralf can see her produced by speaker B in (1) can be argued to be a complement clause (= indirect) question if we consider speaker B’s reply to be an elliptical (i.e. abbreviated) form of ‘I want to know if Ralf can see her’, with all material other than the italicised complement clause undergoing ellipsis (i.e. being ‘silent’). 53 specifier position in a phrase being a position in front of the head word of the phrase – so that Ralf can likewise be said to be the specifier of the auxiliary can in a structure like (2) above). As the brief outline of the syntax of main-clause wh-questions above illustrates, the derivation (i.e. formation) of a main-clause wh-question like Who can Ralf see? involves two different structural dependencies. One of these is a C-T dependency (i.e. a dependency between between C and T), in that C attracts the auxiliary can to move from T into C. The other is a C-wh dependency (i.e. a dependency between C and a wh-word), in that C attracts the wh-word who to become the specifier of C. If – as claimed by DDM – people with SLI have problems in handling structural dependencies between constituents, we’d expect to find that they have problems with the syntax of wh-questions: more specifically (VB claim), we’d predict that they have problems with both auxiliary inversion (because this involves a C-T dependency) and with wh-movement (because this involves in a C-wh dependency). VB’s paper sets out to test this prediction. The nature of VB’s study VB’s study included 15 SLI subjects aged from 11;3 to 18;2, their performance being compared to that of two groups of TD (typically developing) children, 12 grammar-matched children aged from 5;3 to 7;4, and 12 vocabulary-matched children aged from 7;4 to 9;1. (For profiles of the children, see VB p.159.) Data were collected on wh-questions170 containing who, what and which by getting the subjects to play a version of Cluedo in which target wh-questions were elicited by prompts such as those in (9) below: (9) Prompts and target responses for object questions Prompt Target response Mrs Peacock saw someone in the lounge. Ask me who Who did Mrs Peacock see in the lounge? Mrs Brown placed something in the library. Ask me what What did Mrs Brown place in the library? Professor Plum wore a coat. Ask me which one Which coat did Professor Plum wear? Results of VB’s study The table in (10) below (adapted from VB’s table 4) reports on the types of wh-question errors made by three groups of subjects in VB’s study. (10) Types of error produced by the subjects in the VB study SLI subjects Younger TD controls 0/15 (0%) 6/12 (50%) No errors 3/15 (20%) 4/12(33%) AUX errors 0/15 (0%) 1/12 (8%) WH errors 12/15 (80%) 1/12 (8%) WH and AUX errors Older TD controls 12/12 (100%) 0/12 (0%) 0/12 (0%) 0/12 (0%) The column headed SLI subjects tells you that none of the 15 SLI children in the study achieved errorfree performance on wh-questions, that 3 of them made errors only with auxiliary inversion, that none of them made errors only with wh-movement, and that 12 of them made errors with both wh-movement and auxiliary inversion. The column headed Younger TD controls tells you that of the 12 children in the younger TD control group (aged 5-7 years), 6 produced no errors of any kind, 4 only made errors with auxiliary inversion, 1 only made errors with wh-movement, and 1 made errors with both wh-movement and auxiliary inversion. The column headed Older TD controls tells you that of the 12 children in the older TD control group (aged 7-9 years), all produced completely error-free performance on wh-questions, and hence made no errors with either wh-movement or auxiliary inversion. 170 VB collected data on both subject and object wh-questions. A subject wh-question is one in which the wh-expression is the subject of the relevant verb (e.g. Who saw you? where who is the subject of saw); an object whquestion is one in which the wh-expression is the object of the relevant verb (e.g. Who did you see? where who is the object of see). Here, I concentrate on the wh-object questions produced by the SLI subjects, partly because these are the questions which posed greatest problems for the SLI subjects, and partly because the syntax of wh-subject questions in adult English is a matter of controversy (e.g. about whether they involve wh-movement or not, and how they can satisfy the WH-CRITERION without auxiliary inversion). 54 Errors made by VB’s subjects Examples of sentences produced by the subjects in VB’s study which illustrate both the kind of auxiliary errors made by their SLI subjects and the kind of wh-errors they made are given below: (11)(a) (b) (c) Who Miss Scarlett saw somebody?171 Which Reverend Green open a door?172 What did Colonel Mustard had something in his pocket?173 In order to understand what’s going in here, let’s take a closer look at the derivation of sentence (11a). The V/verb see is merged with the pronoun somebody to form the VP/verb phrase see somebody. A T constituent containing a past-tense affix (below denoted as Af) is then introduced into the derivation, and merged with the VP already formed, and with the subject Miss Scarlett, forming the TP Miss Scarlett Af see who. A null interrogative C is then merged with this TP, forming the CP shown in simplified form below: (12) [CP [C ø] [TP Miss Scarlett [T Af] [VP [V see] somebody]]] The specifier position in front of C is filled by directly merging the interrogative pronoun who in spec-C, so deriving the structure: (13) [CP Who [C ø] [TP Miss Scarlett [T Af] [VP [V see] somebody]]] When (as here) a tense affix is immediately adjacent to a following verb, it is lowered onto the verb in the PF/morphophonological component of the grammar, via an operation traditionally referred to as Affix Hopping, as shown by the arrow below: (14) [CP Who [C ø] [TP Miss Scarlett [T Af] [VP [V see ] somebody]]] The resulting string see+Af is ultimately spelled out as saw, and consequently the overall structure in (14) is ultimately spelled out as the sentence (11a) Who Miss Scarlett saw somebody? The resulting sentence (11a) illustrates a double dependency failure. First of all, the SLI subject who produces (11a) has failed to master the C-T dependency, in that C fails to attract the affix in T to move into C. Moreover, the same individual has also failed to master the C-wh dependency in that the specifier position in front of C is filled by merging the wh-pronoun who in spec-C, rather than by moving who from (what should have been) its initial position as the (direct object) complement of the verb see into spec-C. By contrast, a fluent native speaker of English would have derived the sentence as follows. The V/verb see is merged with its complement who to form the VP/verb phrase see who. A past tense affix (Af) is then merged with this VP and with the subject Miss Scarlett to form the TP Miss Scarlett see who. This TP is in turn merged with a null interrogative complementiser to form the CP shown below: (15) [CP [C ø] [TP Miss Scarlett [T Af] [VP [V see] who]]] The null complementiser then attracts the tense-affix in T to move into C, and at the same time also attracts the wh-word who to move into spec-C, so deriving the following structure: (16) [CP Who [C Af] [TP Miss Scarlett [T Af] [VP [V see] who]]] Because the tense affix in C is not immediately followed by a verb, it undergoes DO-SUPPORT – i.e. the (meaningless) ‘expletive’ or ‘dummy’ stem DO is attached to the affix in order to support it (i.e. in order to ensure that it has a verbal stem to attach to), and the resulting string DO+Af is eventually spelled out as did – with the consequence that the overall structure in (16) is spelled out as the sentence Who did Miss Response to ‘Miss Scarlet saw someone in the lounge. Ask me who’ (the target response being Who did Miss Scarlet see in the lounge?) 172 Response to ‘Reverend Green opened a door. Ask me which one’ (the target response being Which door did Rev. Green open?). 173 Response to ‘Something was in Colonel Mustard’s pocket. Ask me what’ (the target response being What was in Colonel Mustard’s pocket?). 171 55 Scarlett see? However, as already noted, the corresponding sentence (11a) produced by the SLI subject shows that neither the C-T dependency (involving movement from T to C) nor the C-wh dependency (involving movement of a wh-word from within VP into spec-C) have been mastered. Sentences like (11a) thus appear to provide empirical support for the Dependency Deficit model. Now consider another sentence produced by one of VB’s SLI subjects, namely (11b) Which Reverend Green open a door? This would appear to be derived as follows. The V/verb open is merged with its (direct object) complement a door to form the VP open a door. A null T constituent (ø) is then merged with this VP and with its subject Reverend Green to form the TP Reverend Green ø open a door. The resulting TP is merged with a null interrogative complementiser to form the structure shown below: (17) [CP [C ø] [TP Reverend Green [T ø] [VP [V open] a door]]] The specifier position in front of C is filled by directly merging the wh-word which in spec-C, so deriving the structure: (18) [CP Which [C ø] [TP Reverend Green [T ø] [VP [V open] a door]]] Since the T position appears not to contain a past tense affix, there is no affix to lower onto the verb open, with the result that the structure in (18) is eventually spelled out as sentence (11b) Which Reverend Green open a door? Like (11a), sentence (11b) exemplifies a double dependency failure, in that the SLI subject who produces the sentence has not mastered either the C-T dependency (i.e. the need to fill the C position by moving an affix or auxiliary in T into C), or the C-wh dependency (i.e. the need to fill the spec-C position with a wh-word via movement rather than merger). Finally, let’s see look at what goes wrong in (11c) What did Colonel Mustard had something in his pocket? Let us suppose that this is derived as follows. The verb have is merged with the pronoun something and with the prepositional phrase in his pocket to form the VP have something in his pocket. A past tense affix (Af) then merged with this VP, and with its subject Colonel Mustard, forming the TP Colonel Mustard Af have something in his pocket. The resulting TP is in turn merged with a null interrogative complementiser, forming the structure shown below: (19) [CP [C ø] [TP Colonel Mustard [T Af] [VP [V have] something in his pocket]]] Because an affix can only be attached to an immediately fllowing verb, and the past tense affix is eventually attached to the verb have (with the resulting have+Af string eventually being spelled out as had), it would appear that the tense-affix remains in T, and at no point moves into C. This being so, it follows that the head C position of CP in (19) must be filled by directly merging the auxiliary did in C. Likewise, the specifier position in front of C is filled by directly merging the wh-word what in spec-C. These two merger operations result in the structure shown below: (20) [CP What [C did] [TP Colonel Mustard [T Af] [VP [V have] something in his pocket]]] The past tense affix in T undergoes Affix Hopping in the PF/morphophonological component of the grammar, forming the string have+Af which is eventually spelled out as had. Consequently, the overall structure in (20) is eventualy spelled out as sentence (11c) What did Colonel Mustard had something in his pocket? Once again, the structure involves a double-dependency error, with the SLI subject in question failing to master the C-T dependency (i.e. failing to understand that C is filled by movement rather than merger), and likewise failing to master the C-wh dependency (i.e. failing to understand that spec-C is filled by movement rather than merger). VB’s main claims VB’s two main claims are the following. Firstly, SLI subjects have far more problems with the syntax of wh-questions than language-matched TD controls. And secondly, the pattern of errors made by the SLI subjects differs from the pattern of errors made by the TD subjects: most SLI subjects have problems with both auxiliaries and wh-expressions, whereas most TD subjects have problems with neither (and if they have any problems at all, they tend to have problems only with auxiliary inversion)174. This suggests to 174 VB suggest on p.167 that the one TD subject showing problems with both wh-movement and auxiliary inversion may have ‘an undiagnosed language deficit’. 56 VB that SLI children do not understand the part played by movement operations in establishing syntactic dependencies like the C-T and C-wh dependencies involved in main-clause wh-questions. VB maintain that other theories of SLI are unable to explain their findings. For example, they maintain that Leonard’s Perceptual Deficit hypothesis provides no account of errors such as that in (11c) What did Colonel Mustard had something in his pocket? VB argue that such errors cannot plausibly be taken to involve problems with ‘perception and processing of nonsalient morphemes’. Likewise, VB claim that an approach which assumes a global deficit in all grammatical features (like Gopnik’s 1990 featureblindness account) could not account for the fact that the SLI subjects in their study sometimes produce correct wh-questions, and sometimes produce incorrect forms. Similarly, they maintain (p.171) that approaches which assume a selective feature deficit (e.g. in tense features as in Rice and Wexler 1996, or in agreement features as in Clahsen, Bartke and Göllner 1987) ‘appear too narrow’ in that ‘neither of these accounts would predict problems with WH-operator movement’, so that such accounts ‘do not provide parsimonious explanations of the data for G-SLI subjects’. By contrast, they maintain that their own RDDR model makes precisely the right prediction – namely that because people with SLI have problems in handling structural dependencies between constituents, they will also have problems in handling the CT dependency involved in auxiliarty inversion, and the C-wh dependency involved in wh-movement, and hence that they will show impaired performance on both auxiliary inversion and wh-movement in whquestions like Who did Ralf see? Their overall conclusion (p.170) is thus that ‘The findings of this study confirm the predictions of the RDDR hypothesis and thus support this account of G-SLI’. WORKBOOK SECTION Below, I pose a number of questions designed to help you develop a critical evaluation of VB’s paper. §7.1 Alternative interpretations of VB’s data An interesting question which arises from VB’s research is whether the types of wh-question errors which they report SLIs making doin fact provide strong empirical support for the dependency deficit which they claim, or whether (at least some) of the structures produced by their SLI subjects can be accounted for in ways which do not require us to assume any dependency deficit. For example, why is VB’s claim that an SLI sentence such as: 1. Who Mrs Brown see? shows a failure to understand the C-T dependency (and the need for the head C position of CP to be filled by the auxiliary (di)d) weakened by the observation that adults (in informal speech) frequently give a null spellout to a contracted inverted auxiliary, as in the following sentences (from the Bates files on the CHILDES data-base) produced by mothers talking to children aged 1;8 and 2;4, where the mothers give a null spellout to the parenthesised auxiliaries? 2. Where you going? (are). What she doing? (is). What they got in them? (have). How they sit? (do). Then what she do? (did) And why is the claim that SLI sentences such as 3. What did they drank? show a similar C-T dependency deficit weakened by the claim made by Chomsky (in work since 1995) that movement is a composite operation involving placing a copy of some constituent in a new position, and then subsequently giving the copy in the original position a null spellout (i.e. a ‘silent’ pronunciation, in effect deleting it)? In addition, evaluate the strength of VB’s claim that SLI sentences like 4. Which Reverend Green open a door? involve the wh-word which being positioned in spec-C by merger rather than wh-movement. In this connection, bear in mind that English has structures like what a goal! and how good a goal? in which the indefinite article a can have a wh-expression modifying it (as its specifier). Bear in mind also that Gavruseva and Thornton (2001) report that even typically developing children sometimes prepose a wh-word on its own without pied-piping (i.e. ‘dragging’) along with it material modified by the wh-word, 57 - as illustrated by the structure in 5 below produced by a typically developing 6-year-old (where whose has been preposed without the noun ball that it modifies): 5. Whose do you think ball went in the cage? Finally, assess the strength of the claim made by VB that SLI sentences such as (6) below provide empirical evidence that SLIs fill spec-C via merger rather than movement: 6. Who Miss Scarlett saw somebody? In this connection, bear in mind that David Pesetsky (1997, 1998) has argued that wh-movement may sometimes result in a partial copy of a moved wh-pronoun being left behind in the position out of which the wh-pronoun initially moved, so resulting in a structure such as that in the bracketed relative clause below: 7. He’s someone [who you’re never sure whether to trust him or not] The partial copy that is left behind by movement in such cases (Pesetsky argues) is a pronoun which carries essentially the same (e.g. person/number/gender/specificity) features as the wh-pronoun except for its wh-feature (i.e. the partial copy is a non-wh counterpart of the wh-pronoun). What this could mean is that if a non-specific wh-pronoun moves (e.g. who meaning ‘which person out of an unspecified set of people’), it could leave behind a wh-less non-specific pronoun like somebody in the position out of which it moves. §7.2 Wh-movement in the Leonard corpus Given that VB’s study is experimental in nature (in that they used a particular experimental technique to elicit wh-questions from their SLI subjects), an interesting way of testing their theory empirically is to see whether similar types of wh-question errors are found in a large naturalistic corpus (e.g. a publicly accessible data-base containing transcripts of the spontaneous speech production of SLI children). One such corpus is the Leonard SLI corpus on the CHILDES data-base (MacWhinney 1995), which contains samples of the ‘free speech’ of 11 SLI children. Radford and Lin (2005) searched this corpus for examples of main-clause non-subject175 wh-questions. They found that the SLI children in the Leonard corpus produced a total of 294 questions containing an overt non-subject wh-expression, and that all of these showed adult-like wh-movement. Why do you think it might be that there are no examples of wh-merger structures like (1) Who Miss Scarlett saw somebody? in the Leonard corpus – and what is the potential significance of this for the Dependency Deficit Model? In addition, comment on the potential significance of the absence of wh-in-situ questions like (2) below in the Leonard corpus (and indeed in van der Lely and Battell’s study): (2) They drank what? Would the Dependency Deficit model lead us to expect SLI children to produce wh-in-situ questions like (2)? §7.3 Wh-question errors in the Leonard corpus Below are a representative sample of different types of non-adult-like wh-question structures (for mainclause non-subject wh-questions) produced by SLI children in the Leonard corpus referred to in §7.2 (the child producing each example being identified by a parenthesised letter such as (B) after the example, and the adult counterpart of each sentence being enclosed in inverted commas). 1 Which one I can do? (C ‘Which one can I do?) 2. What Kent’s gonna play with? (C ‘What’s Kent gonna play with?) 3. How you knowed? (E ‘How did you know?’) 175 I.e. questions where the wh-expression is not the subject of the clause containing it. The reason for excluding subject questions is that wh-movement in them is seemingly ‘invisible’ and they do not involve auxiliary inversion (for reasons discussed in Radford 2004). 58 4. What he did? (F ‘What did he do?’) )176 5. What you doing? (E ‘What are you doing?’) 6. What this for? (G ‘What is this for?’) 7. How much we got to do? (J ‘How much have we got to do?’) 8. How you get this out? (A ‘How d’you get this out?’) 9. What this do? (A ‘What’s this do?/What does this do’) 10. How open it up? (B ‘How d’you open it up?’) 11. What say? (B ‘What d’you say/What did you say?’) 12. Where go on? (B ‘Where’s it go on/Where does it go on?’) 13. How much long gonna be? (A ‘How much longer’s it gonna be?’) 14. These do? (C ‘What do these do?’) 15. What is this is? (H ‘What is this?’) What different types of wh-question do we find in sentences 1-15 above, and to what extent do the various question types show the kind of dependency deficit predicted by VB? What is the potential significance of the fact that (as illustrated in the examples in 2 in §7.1) adults often give a null spellout to a contracted inverted auxiliary in a wh-question? What is also the potential significance of the observation by Virginia Valian (1991) that adults in rapid speech styles sometimes give a null spellout to a weak unstressed whword at the beginning of a sentence, hence (e.g.) giving a null spellout to what in What time is it? (More generally, adults sometimes omit one or more unstessed syllables at the beginning of a sentence, so e.g. giving a null spellout to the material marked by strikethrough in It’s a nice day, isn’t it?). You might also care to note that (in a similar vein) Luigi Rizzi (2000) argues that even typically developing children often give a null spellout to weak constituents at the edge (i.e. in the head or specifier position) of CP in a main clause, so that a preposed auxiliary and/or a preposed wh-word are sometimes ‘silent’ if weak (i.e. if they have little phonetic substance). More specifically, prepare analyses of sentences 1, 2, 8, 11, 12 and 15. Assume that you have reached a stage in the derivation of each sentence at which you have formed a CP containing a null interrogative complementiser like that below (where ø marks a indicates that the relevant T constituent is null and so contains no overt auxiliary, and strikethrough indicates that the relevant word ultimately receives a null spellout and so is ‘silent’): (1a) (4a) (5a) (9a) (11a) (14a) (15a) [CP [C ø] [TP I [T can] do which one]] [CP [C ø] [TP He [T Af] do what]] [CP [C ø] [TP You [T are] doing what]] [CP [C ø] [TP This [T Af] do what]] [CP [C ø] [TP You [T Af] say what]] [CP [C ø] [TP These [T Af] do what]] [CP [C ø] [TP This [T is] what]] Assume that T contains a past tense affix in (4a) and (11a), a (third person singular) present tense affix in (9b), and a (third person plural) present tense affix in (14a). Assume also that an affix which remains in T is eventually lowered onto an immediately following verb, but that an affix which moves to C has to undergo DO-support (because there is no verb immediately following it for it to lower onto). Bear in mind in relation to (15) that Chomsky has argued in work over the past decade that movement is a composite operation involving placing a copy of some constituent in a new position, and then subsequently giving the copy in the original position a null spellout (i.e. a ‘silent’ pronunciation, in effect deleting it). 176 The adult counterparts of child questions which differ in form from the corresponding adult questions are as follows: 1. What is this? 2. What are you doing? 3. What is this for? 4. How much have we got to do? 5. How do you get this out? 6. What does this do? 7. How d’you open it up? 8. What d’you (= did you) say? 9. Where does it go on? 10. How much longer is it gonna be? 11. What do these do? 12. Which one can I do? 13. What’s Kent gonna play with? 14. How did you know? 15. What did he do? 59 §7.4 Two types of movement operation Radford and Lin (2005) reported that (on non-subject wh-questions) the SLI children in the Leonard corpus showed 100% correct suppliance of wh-movement, but only 35% correct suppliance of auxiliary inversion. Would the Dependency Deficit Model predict this kind of difference? What if we were to posit that wh-movement and auxiliary inversion differ from each other in that wh-movement is an interpretable movement operation (in the sense that it has an effect on semantic interpretation/meaning), but auxiliary inversion is an uninterpretable movement operation (i.e. one which has no effect on the meaning of a sentence)177. What interpretive effect (i.e. effect on meaning) does wh-movement have? Well, if we follow Radford et al (1999) in supposing that (for languages like English) (i) A clause is only interpreted as a non-echoic question if it is a CP with an interrogative specifier then we can say that the interpretive effect of wh-movement in a question is to ensure that the relevant structure begins with an interrogative wh-expression and so can be interpreted as a wh-question. At first sight, it might seem that auxiliary inversion also has an interpretive effect, in that (we might suppose) a clause is interpreted as a question only if it is a CP containing an auxiliary in the head C position of CP. However, this claim seems untenable for a number of reasons. For one thing, a complement-clause question like the CP bracketed below: (ii) She asked me [CP where [C ø] [TP he [T had] gone]] contains an interrogative wh-word in spec-C but no auxilary in C – which means that it is wh-movement and not auxiliary inversion which is crucial to ensuring that the bracketed clause is interpreted as interrogative. And conversely, some structures containing an inverted auxiliary in C are not interrogative – as can be illustrated in relation to the CP in (iii) below: (iii) [CP Never [C have] I heard such rubbish] If it is indeed the case that wh-movement is an interpretable operation (and thus has an effect on meaning) whereas auxiliary inversion is an uninterpretable operation (which therefore has no effect on meaning), consider what the implications would be of generalising the Uninterpretable Feature Deficit Model of Tsimpli and Stavrakaki (1999) and supposing that SLIs are good at handling interpretable features and interpretable operations, but poor at handling uninterpretable features and uninterpretable operations. Would this account fare better than the Dependency Deficit Model in accounting for why SLIs appear to be much better at wh-movement than at auxiliary inversion? §7.5 Overall verdict In the light of the questions asked above, what is is your overall verdict on the strengths and weaknesses of Heather van der Lely’s Dependency Deficit model? 177 Chomsky (1999) maintains that this is a consequence of wh-movement being a syntactic operation, but auxiliary inversion being a PF (i.e. morphophonological) operation – but I will not go into relevant technical details here. 60 8: Empirical study I: Acquisition of past-tense marking This chapter (and the next 3) aim to show you how to do a small-scale empirical178 research project investigating particular aspects of the grammatical development of an SLI child, how to analyse the data, how to use your research results to evaluate a number of different theories of SLI, and how to write up your project. The data for your project come from a set of transcripts of the speech production of a 4-year-old American boy with SLI, known as JC. Brief details of JC and a copy of the transcripts can be found in chapter 13. In this chapter, I show you how to use the JC corpus to undertake an empirical study of The acquisition of past tense marking on main verbs by a 4-year-old American boy with SLI. Your study might be organised into chapters/sections and subsections along the following lines. 1. Background (about 25% of your overall study) 1.1 Introduction Start with a paragraph outlining the kind of developmental disorder which SLI involves (summarised on p.4 of this book: see Bishop (1997), Leonard (1998), and the collection of papers in Bishop and Leonard (2000) and Levy and Schaeffer (2003) for more detailed discussion of diagnostic criteria for SLI), and point out that various aspects of grammar are reported to be impaired in SLI children, including their ability to mark tense in obligatory contexts. There are a wide range of different models of SLI which seek to account for the nature of the grammatical impairment in SLI children, and for the purposes of the present study you are going to examine just a few of these (e.g. you might choose any three of the Perceptual Deficit, Rule Deficit, Agreement Deficit and ATOM models). Your aim is to do a small-scale empirical study designed to evaluate each of the models, by looking at the production of regular and irregular past tense main verbs by a 4-year-old American boy with SLI. 1.2 Outline of the morphophonology of past tense marking in English In this section, you should provide a brief account of the morphophonology of past tense marking in English. The dual mechanism model of the acquisition of morphology (outlined e.g. in Pinker and Prince 1988, and Pinker 1991) maintains that irregular forms are memorised forms which are stored/listed in the mental lexicon, whereas regular forms are computed or derived via application of morphological rules like those sketched informally in (1) below (with morphemes enclosed in curly brackets): (1) A regular verb carries the suffix {s} if third person singular present {d} if past, perfect or passive {ing} if progressive or gerund {ø} otherwise The precise phonological form which a morpheme is given in a particular structure is determined by spellout rules like (4) below179: (2) {d} is spelled out as: |Id| when attached to a stem ending in an alveolar stop – i.e. |t| or |d| (e.g. padded, batted) |d| when attached to a stem ending in another voiced segment180 (e.g. moved, sneezed, paid) |t| when attached to a stem ending in another voiceless segment181 (e.g. passed, packed, laughed) So, for example, the lexical entry (i.e. entry in the dictionary) for the regular verb DIE will contain simply the stem form die: its past tense form will be generated by adding the the suffix {d} to the stem form in 178 An empirical study is one which involves analysing a set of data in order to test one or more research hypotheses. Since children are unable to read when they produce their earliest verb-forms, what is crucial is how such forms are pronounced, not how they are written. Hence, I ignore the fact that e.g. past tense {d} is sometimes spelled -ed. 180 Since all vowels are voiced, this means ‘when attached to a stem ending in a vowel, or a voiced consonant other than |d|’. 181 In other words ‘when attached to a stem ending in a voiceless consonant other than |t|’. 179 61 accordance with the second line of rule (1), so deriving die-d; the {d} suffix will be spelled out as |d| in accordance with the second line of rule (2), so that the word is pronounced |da Id|. By contrast, the lexical entry for the irregular verb CATCH will specify that it has the irregular past/perfect/passive form caught, and the fact that the verb is listed as having an irregular past/perfect/passive form will block application of the regular d-rule in (1) to irregular verbs like CATCH. Empirical research is about testing research hypotheses, so in the next few sections you should provide a short summary of the overall claims made by each of the models of SLI which you have decided to evaluate, and then go on to say what specific prediction each makes about what SLI children do in past tense contexts182 (these predictions being the research hypotheses which you are going to test). You should provide evidence of having read the key research paper/s on each model you discuss (e.g. by quoting a couple of key sentences from it/them). 1.3 Outline of the Perceptual Deficit model of SLI In this section you should provide an outline of the Perceptual Deficit model183, noting that it claims that consonantal inflections pose more perceptual problems for SLI children than vocalic inflections, and so predicts that SLI children will perform worse on producing the past tense of regular verbs like played (where past tense is marked by the consonantal inflection -d) than on irregulars like gave where past tense is marked by vowel-change (replacing the |I| vowel of the citation form184 give by an [eI] diphthong). But, as we saw in chapter 2, things are not quite as straightforward as that, for two reasons. Firstly – as we see from (2) above – the regular past tense morpheme {d} has the three allomorphs |t|, |d| and |Id| and we would therefore expect SLI children to perform better on the last of these three because it contains a vowel: as Leonard (1989, p.187) notes, this is because ‘although all are low in phonetic substance, the former (= |Id|) receives the benefit of greater acoustic energy from the vowel’. Moreover, if consonant clusters cause additional perceptual problems, we’d expect the performance of SLI children on the purely consonantal |t,d| allomorphs of past tense {d} to be worse when these are added to a verb stem ending in a consonant (as in e.g. dumped which contains the cluster |mpt|) than to one ending in a vowel or diphthong (as in tried, for example). An additional complicating factor is that not all irregular pasts are marked by vowel-change alone (consonant change being used to mark the difference between the citation form send and the irregular past tense form sent, for example). So, the Perceptual Deficit model would lead us to expect that an SLI child should perform better on |Id| than on purely consonantal allomorphs of regular past tense {d} and better on the latter when they don’t give rise to a consonant cluster than when they do, and that they should perform better on irregulars which mark past tense by vowel change alone than on other types of irregular. 1.4 Outline of the Rule Deficit model of SLI In this section you should provide an outline of the Rule Deficit model185, which claims that SLI children have a genetic rule-deficit that makes it impossible for them to acquire any regular morphological rules. They are therefore unable to acquire the regular past tense d-rule, and this predicts that they will be unable to create novel or over-regularised past tense forms186. Because of their genetic rule deficit, the only learning mechanism which SLI children have is memorisation, with the consequence that they have to 182 I use this rather vague formulation here because some models of SLI make predictions not only about the morphology of the verbs used by SLI children in past tense contexts, but also about the case properties of their subjects – and you may want to test the latter as well as the former in your study. 183 Only if you have decided to include this model as one of the models that you are testing, naturally. 184 The citation form of a word is the form under which it is listed in a dictionary 185 Only if you have decided to include this as one of the models that you are testing. 186 However, it should be noted that Ullman and Gopnik (1994) maintain that in spite of their inability to form implicit (i.e. subconsciously internalised) rules, SLI children who have undergone extensive therapy may learn an explicit (i.e. consciously memorised) rule taught to them by therapists or teachers telling them to ‘Put -d on the end of a verb in a past tense context’. This means that the production of over-regularised forms does not necessarily ‘prove’ that a child has developed a subconsciously internalised past tense formation rule. However, JC is only 4 years of age, and it is unlikely that he is old enough for therapists to attempt to teach him abstract grammatical rules. 62 memorise regular and irregular inflected forms alike. Since memorisation of a given form improves with increased exposure to the relevant form, we therefore expect to find a frequency effect (viz. that the more often a child hears a given past tense form, the more often the child is likely to produce it correctly). More specifically, if Gopnik and Crago are right in claiming that SLI children have a rule-deficit, we should expect to find a frequency effect with regular as well as irregular verbs (since, according to them, both sets of verbs are acquired via the same mechanism of memorisation); but if Gopnik and Crago are wrong and SLI children (like normally developing children) learn regular forms by rule and irregular forms by memorisation, we should expect to find a frequency effect with (memorised) irregulars, but not with (rule-derived) regulars. 1.5 Outline of the Agreement Deficit Model In the next section, you should provide an outline of the Agreement Deficit model187, which claims that children with SLI have considerable problems in acquiring uninterpretable agreement features, but few problems in acquiring interpretable features like tense. Among the predictions made by the model are that SLI children should fare much better on past tense forms (because these mark an interpretable past-tense feature) than on third person singular present-tense/3SgPres forms (because these mark both an interpretable present-tense feature and uninterpretable third-person-singular agreement features, and their uninterpretable agreement features will therefore make 3SgPres forms harder to acquire). 1.6 Outline of the Agreement-and-Tense-Omission (ATOM) model of SLI In the next section, you should provide an outline of the Agreement-and-Tense-Omission/ATOM model188, which claims that SLI children go through an Extended Optional Infinitives/EOI stage during which they sometimes fail to mark tense and/or agreement in finite contexts (i.e. in contexts where adults use an auxiliary or main verb marked for tense and agreement). The presence or absence of agreement on the verb will affect the case assigned to the subject (in that a nominative subject is used when agreement is marked and a default accusative subject when it is not). ATOM makes the following prediction about how an SLI child at the Extended Optional Infinitives/EOI stage will reply to a past tense question like ‘What did Daddy do yesterday?’ One possibility is that the child will mark both tense and agreement: if so, the verb play will carry the -d suffix (because it is marked for past tense) and the subject will be nominative (because agreement is marked), giving He played with me. A second possibility is that the child may mark tense on the verb, but not agreement: because past tense is being marked, the verb will then carry the past tense suffix -d in accordance with line 2 of rule (1), but because agreement is not being marked, the subject will have accusative case by default, resulting in Him played with me. A third possibility is that the child may mark agreement on the verb, but not tense; because tense is not being marked, the verb will not carry past tense -d and instead will be a bare infinitive form carrying a null affix in accordance with the last line of rule (1); but because agreement is marked, the subject will be nominative so that we have He play with me. The fourth and final possibility is that the child may use the verb PLAY without marking either tense or agreement on it: absence of tense will mean that the verb does not carry -d, and absence of agreement means that its subject will get accusative case by default, giving rise to Him play with me. Because ATOM does not make any claims about whether agreement would be expected to be more or less severely impaired than tense, it doesn’t make any precise predictions about whether overall there will be (e.g.) more agreement-omission errors (with default accusative subjects) than tense-omission errors (or conversely). 1.7 Summary of research hypotheses being tested In this section, you should summarise the set of research hypotheses you have set out to test in your project – e.g. along the lines shown below: 187 188 Only if you have decided to include this as one of the models that you are testing. Only if you have decided to include this as one of the models that you are testing. 63 (3) Perceptual Deficit model SLI children perform better on (e.g. irregular) verbs where past tense is marked by a vowel than on (e.g. regular) verbs where it is marked by a consonant (4) Rule Deficit model SLI children will not produce spontaneous novel or over-regularised pasts189, and will perform better on more frequent regular and irregular past-tense verb forms than on less frequent forms (5) Agreement Deficit model SLI children have problems with uninterpretable agreement features, and so will perform better on past tense forms (because these mark an interpretable past-tense feature) than on third person singular present tense forms (because these mark not only an interpretable present-tense feature but also uninterpretable third-person-singular agreement features) (6) Agreement-and-Tense-Omission/ATOM model In past tense contexts, children alternate between producing past tense forms like played and bare (infinitive) forms like play, and in both types of structure alternate between using nominative subjects like I/we/he/she/they and default accusative subjects like me/us/him/her/them. 2. Research results (about 25% of the overall study) 2.1 Introduction Begin with an Introduction (section 2.1) in which you note that you are setting out to test the predictions made by your chosen theories of SLI by examining the types of structure produced by JC in contexts where adults would use a past-tense main verb. In order to do this, you first need to draw up a list of sentences containing main verbs which JC appears to use in past tense contexts (and you should include this list as an Appendix to your eventual project). In order to help you with this task, below I have listed sentences produced by JC containing (italicised) main verbs used in a past tense context (in the sense that the italicised verbs forms arguably occur in a context where an adult would use a past tense main verb): (7) List of (italicized) main-verb forms potentially used by JC in past tense contexts 5. He see snow on he chimney 16. Me used to have a dog, but somebody take it away 18. Now, going home cause it melted 23. Me got one from Michael 27. Me got chicken pox 32. Me fall asleep on the couch 33. Me said, me gotta hurry up and go up 35. Come up there, then me sleep up there 36. Me fall asleep up there 81. Like me see on the TV 97. No, somebody else taked it 101. Somebody else asked my mom to play outside with them 102. No one shoveled it 103. Me just jumpovered it 105. He shoveled someone else 112. He burn heself here 113. He eat it 114. No, took it off of...then he eat it 120. The teacher said when you eat a lot of food you got food in your mouth 125. I think this, he...umm, oh, he dump it 126. He shoveled him truck 127 And then he dump it 130. He shoveled him truck 131. Then he dump it 132. And then he drived away 133. Because, he want to put it 144. Then, he knocked him window 170. Long time ago you give me that first 174. He family, he lost he family 176/7. And he can't go and he family... die 179. He lost him duck 193. Oh, he caught me 198. Long time ago I have a big eye 208. An owl did this with he eyes 210. And he, hooh, and someone look at there and said ah! 211. And then, he scare them and said ha, ha, ha 213. Then, he talk to himself 214. Some wake up middle of night 215. Then, when someone go down, and the owl scare them 229. We see clown at...umm... 230. I see clown at a post office 231. Them have a party, and clown give me a balloon 232. He give a plane balloon 236. I never saw one of these stove 251. You lost one of these 189 As noted earlier, the only way SLI children could produce such over-regularised past-tense forms is if they have consciously learned an explicit rule taught to them by a therapist or teacher. 64 259. Peter laughed you 267. Me teacher make cake 268. Her make it for Ms Peggy a long time ago 277. Her give me dad a lobster 278. Me mom put in here, cook them 279. Forgot to take them eyes out 280. And then, it give it to mom 281. He say, put it down 282. And then her say, ahhh! 283. And then her put on the floor, and we scare her 284. Her say, ahh it's moving 285. And then, them cook them up 286. And then it scared mom 290. And me dad eat it 291. Daddy cook it. 298. I know, he wanned to go and drop it 300. He jumped out 301. He bit me 303. Then, her drink some water 303 Water make cookie all gone 306. Maybe some lobster pinch him 311. Her have a snake in the sink 313. Then grandma get bitten by a snake 314. Then her got hurt 315. Then, me and xxx drop a xxx, then it hurt me 316. He try to eat me up 321. Long time ago, I go camp and hiking at the same time 323. I say, and I eat at hiking 324. And then at hiking, I xxx a picnic, so we eat 326. Then a bee eat a little bit my food 327. Then me said, oh! 328. Then me take it xxx 329. Then me go camping 330. Me eat all our food 337. Me mommy show me to make Easter eggs 339. I forgot 365. I got my hair from barber 366. But them cut my hair real tiny 379. He cut me You should include the list in (7) as an Appendix to your project. Your first task is to use the list in (7) to compile a frequency table like the (partial) table in (8) below, showing how often JC uses particular verbforms in past tense contexts: (8) Raw frequency of verb-forms used by JC in past tense contexts Type Verb A: correct form B: bare form 1. regular DUMP dump = 3 1. regular SCARE scared = 1 scare = 3 1. regular SHOVEL shovelled = 4 2. novel JUMPOVER jumpovered = 1 3. mixed BURN burn = 1 4. Irregular DRIVE 4. Irregular EAT eat = 7 4. Irregular LOSE lost = 3 4. Irregular TAKE took = 1 take = 2 5. Invariable irregular CUT cut = 2 C: other form drived = 1 taked = 1 In the first column of the table, I’ve classified verbs into five types in respect of how they form their past tense. Regular verbs are those which have a regular adult past tense form ending in {d}. Novel verbs are those like JUMPOVER (in this instance, created by fusing jump and over into a compound word) which have no adult counterpart: such words typically have regular past tense forms (e.g. if we created a novel verb GLURG, it would have the regular past tense form glurged). Mixed verbs are those like BURN which can either have a regular past tense form ( = burned) or an irregular past tense form (= burnt). Irregular verbs are those which have an irregular past tense form which is distinct from the bare/infinitive form of the verb (e.g. DRIVE which has the irregular adult past tense form drove). Invariable irregulars are verbs like CUT which have an irregular past tense form identical to their bare/infinitive form – as we see from sentences like ‘He didn’t want to cutINFINITIVE the grass, but reluctantly he eventually cutPAST it’. In the second column, I’ve listed verbs alphabetically by type. In the third column (labelled A: correct form), the fourth column (labelled B: bare form), and the fifth column (labelled C: other form), I’ve shown the raw frequency of individual verb-forms (a superscript number being used to indicate how often each particular verb-form was produced by JC in a past tense context). So, for example, the entry for TAKE says that (in past tense contexts) JC used the correct adult form took once, the bare form take twice, and the over-regularised form taked once. Of course, the table I have produced in (8) is a partial table showing only some of the verb-forms which JC uses in past tense contexts. You must use the data in (7) to produce a complete table of your own which shows all the verb-forms produced by JC in past tense contexts. 65 Your own (complete version of) the frequency table in (8) should be included in an Appendix at the end of your project. You can use this table as the basis for a number of simple frequency calculations in the next few sections of your study, and use the research results you obtain to test the predictions made by the particular theories of SLI that you are looking at. The particular calculations you need to make will depend on the particular models of SLI that you are testing (so your particular project may not need to include some of the sections below). 2.2 Calculating JC’s percent suppliance of correct regular and irregular past tense forms Some models of SLI make specific claims about whether SLI children do or don’t perform better on irregular verbs than on regular verbs. In order to test such claims, we therefore want to compare the frequency with which JC correctly marks past tense on regular verbs with the frequency with which he correctly marks past tense on irregular verbs. One way of doing this is in terms of the formulae shown below (NB no. = number) (9) Percent suppliance of correct past = tense form for regular verbs no. of tokens of correct regular past forms x 100 no. of obligatory contexts for regular past forms (10) Percent suppliance of correct past = tense form for irregular verbs no. of tokens of correct irregular past forms x 100 no. of obligatory contexts for irregular past forms What (10) means is as follows. For all regular (i.e. type 1) verbs in your own complete version of table (8), count up the number of tokens (i.e. examples/occurrences) of correct forms listed in column A, multiply this sum by 100, and then divide the resulting total by the number of times the relevant verbs were used in past tense contexts (which you can arrive at by adding up the number of tokens of correct, bare and other forms in columns A, B and C). So, if we did this calculation for the partial table in (8), we’d end up with 5 tokens of 1A forms (1 occurrence of scared and 4 of shoveled). We’d then multiply this figure by 100, giving a total of 500. We’d then divide this total by the number of tokens of verb-forms in the cells in 1A, 1B and 1C together, i.e. 11 (comprising 4 occurrences of scared, 1 of shoveled, 3 of dump and 3 of scare), giving us an overall percent score of 45% suppliance of correct past tense forms for regular verbs (i.e. 500 ÷ 11). What (10) means is this. For all type 4 verbs in your list (i.e. irregular verbs which have a past tense form distinct from their bare form, and which do not have an alternative regular past tense form as well190), count up the number of tokens of correct forms listed in column A, multiply this sum by 100, and then divide the resulting total by the number of times the relevant verbs were used in past tense contexts (which you can calculate by adding up the number of tokens of correct, bare and other irregular forms in columns A, B and C). So, if we did this calculation for the partial table in (8), we’d end up with 4 tokens of 4A forms (3 occurrences of lost and 1 of took). We’d then multiply this figure by 100, giving a total of 400. We’d then divide this total by the number of tokens of regular verb-forms in the cells in 4A, 4B and 4C, i.e. 15 (comprising 3 occurrences of lost, 1 of took, 7 of eat, 2 of take, 1 of drived and 1 of taked), giving us an overall score of 27% suppliance of correct past tense forms for irregular verbs (i.e. 400 ÷ 15). If these scores were representative of JC’s overall performance (and you obviously cannot assume that they are, because they are computed on the basis of the partial table in 8, and your results need to be computed in relation to a complete counterpart of the table in 8), they’d suggest that JC performs substantially better on regular than irregular verbs. In chapter 3 of your project (where you analyse your research results), you will eventually discuss whether your results are compatible with each of your chosen theories of SLI. 190 We exclude verbs like CUT from this count, for the obvious reason that if a child produces the form cut in a past tense context, you cannot be sure whether he is using a past tense form or a bare (infinitive) form. We also exclude verbs like BURN, because alongside the irregular past tense form burnt they allow the alternative regular form burned. 66 2.3 Testing the Perceptual Deficit model Leonard’s Perceptual Deficit Hypothesis maintains that the problems which SLI children have with certain grammatical morphemes are attributable to a perceptual deficit. The relevant morphemes, he claims, cause perceptual difficulties because of their low perceptual salience; and he further maintains that vowels are more perceptually salient (i.e. easier to perceive) than consonants. If this is so, we would expect to find that SLI children perform better on past tense forms where the difference between the past tense form and the bare/infinitive form is marked by a vowel (as in see/saw), than on those where it is marked by a consonant (as in play/played). But the picture is clouded somewhat by the fact that some past tense forms are marked by both a vowel and a consonant (e.g. as in wait/waited or sleep/slept) – and it is not clear what Leonard’s theory would predict about how well SLI children fare on correctly marking past tense on these forms (the vowel having a high perceptual salience, and the consonant having a low perceptual salience, and the overall verb form having two markers of past tense rather than one). So, the first thing we need to do in order to test Leonard’s Perceptual Deficit model is to draw up three lists of verbs used in past tense contexts by JC: (i) those whose past tense form is marked by a consonant alone, (ii) those whose past tense form is marked by a vowel alone, and (iii) other past tense forms (marked by both a vowel and one or more consonants). For each verb form on each list, we need to say frequently he supplied the correct form, and how frequently he supplied incorrect forms. I have drawn up three partial tables below, to give you some idea of what your tables might look like. You need to exclude from your tables any verb whose past tense form is identical to its bare/infinitive form (e.g. cut, for the obvious reason that if a child says cut in a past tense context, you can’t tell whether he is using the past tense form cut or the infinitive form cut). (11) List of forms used by JC in contexts where adults use a consonant-marked past-tense form Verb A: Correct forms B: Incorrect forms ASK asked = 1 HAVE have = 3 SCARE scared = 1 scare = 3 (12) List of forms used by JC in contexts where adults use a vowel-marked past-tense form Verb A: Correct forms B: Incorrect forms DRINK drink = 1 SEE saw = 1 see = 4 TAKE took = 1 take = 2; taked =1 (13) List of forms used by JC where adults use a vowel- and-consonant-marked past-tense form Verb A: Correct forms B: Incorrect forms SAY said = 5 say = 4 SLEEP sleep = 1 WANNED waned = 1 want = 1 Note that in classifying past-tense verb-forms into the three types listed above, you have to look at differences in the spoken form of the past tense and the corresponding bare infinitive – not at differences in the written language. It will help you if you do a phonetic transcription of each past tense and corresponding bare form. Once you’ve drawn up complete versions of the partial lists in (11-13) above, you can then move on to calculate JC’s mean percent correct score for each of these three groups of verbs, in terms of the following calculation: (14) % suppliance of correct = past-tense forms no. of tokens of correct forms x 100 no. of tokens of correct forms + no. of tokens of incorrect forms 67 So, the percent suppliance of correct forms would be 25% for the consonant-marked forms in table (11) (i.e. only 2 forms correctly marked for past tense out of a set of 8 forms occurring in past tense contexts), 20% for the vowel-marked forms in table (12) (i.e. 2 correct forms in 10 attempts), and 50% for the consonant-andvowel-marked forms in table (13) (i.e. 6 correct forms in 12 attempts). 2.4 Testing the Rule Deficit model Gopnik and Crago’s Rule Deficit Hypothesis claims that SLI children lack the ability to form regular rules, and that they memorise all inflected verb forms (regular and irregular alike). If Gopnik and Crago are right, we should expect to find a frequency effect with regular as well as irregular verbs (since both sets of verbs are claimed by Gopnik and Crago to be acquired via the same mechanism of memorisation); but if Gopnik and Crago are wrong and SLI children learn regular forms by rule and irregular forms by memorisation, we should expect to find a frequency effect only with irregulars, not with regulars (because all regular past tense forms will then be formed by application of the regular past tense d-rule). In order to test for frequency effects, we need information on how frequently particular past tense forms occurred in JC’s speech input. Unfortunately, we don’t have any information on this, so the best guess we can make at input frequency is to use the figures from a frequency dictionary to estimate the relative frequency of different past tense forms in his speech input. The only frequency dictionary currently available for American English is Carroll (1971): it’s not ideal, because it’s based on written American English (whereas the speech input to JC will largely have been a particular variety of spoken American English) – but it’s the best we can do. What you need to do is to compile two frequency tables like the partial tables shown in (12) and (13) below – one for irregular verbs of type 4 (i.e. those which have a distinctive irregular past tense form and which do not also have an alternative regular past tense form), and another for regular verbs of type 1. Arrange the verbs in order of their adult frequency, with the most frequent verbs at the top of the list and the least frequent at the bottom. List the correct (adult) past tense form of the verb in column 1, the raw frequency per million words of the relevant form given in Carroll’s dictionary (i.e. the number of times it occurred per million words in Carroll’s corpus) in column 2191, and JC’s suppliance of the correct form in column 3 (where the figure 5/9 for said means that he used the verb SAY in past tense contexts on 9 occasions, and on 5 of these he supplied the correct past tense form said): (15) Table of frequency of adult irregular past tense forms and JC’s suppliance of correct forms adult past tense form adult frequency per million words JC’s suppliance of correct form had 20511 0/3 said 15309 5/9 did 7169 1/1 bit 600 1/1 ate 440 0/7 forgot 225 2/2 191 Carroll gives the following frequencies (per million words in adult English) for the past tense forms of irregular verbs used in past tense contexts by JC: had = 20511; said = 15309; did = 7169; made = 7073; came = 4914; went = 4132; put = 3942; found = 3362; saw = 2900; got = 2626; took = 2490; cut = 1757; gave = 1534; brought = 1357; lost = 820; caught = 793; fell = 790; bit = 600; hurt = 457; ate = 440; drove = 361; forgot = 225; slept = 200; woke = 133; drank = 106; burnt = 43; The corresponding frequency figures for regular verbs used by JC in past tense contexts are as follows: used = 5607; looked = 3197; asked = 2924; wanted = 1637; tried = 1077; played = 810; laughed = 639; showed = 478; jumped = 476; died = 459; dropped = 427; talked = 415; grabbed = 161; melted = 152; scared = 151; cooked = 147; knocked = 139; dumped = 38; pinched = 18; shovelled = 12. 68 (16) Table of frequency of adult regular past tense forms and JC’s suppliance of correct forms adult past tense form adult frequency per million words JC’s suppliance of correct form looked 3197 0/1 asked 2924 1/1 wanned192 1637 1/2 jumped 476 1/1 died 459 0/1 dropped 427 0/1 Once you’ve compiled your own complete versions of the (partial) frequency tables in (15) and (16), you then need to establish whether you have evidence for a frequency effect with irregular verbs on the one hand, and with regulars on the other. You need to divide the verbs in each table into two groups – those whose past tense form occurs relatively frequently in adult English (let’s call them frequent past-tense forms), and those whose past tense forms occur relatively infrequently (let’s call them infrequent pasttense forms). It’s up to you to decide how you are going to classify verbs as frequent or infrequent – e.g. maybe you will decide to take past-tense forms with an adult frequency of more than 2,000 (or 1,500? or 1,000? or 500? or 250?) to be frequent, and others to be infrequent. For the sake of argument, let’s suppose that we take verbs with an adult frequency of more than 1,000 occurrences per million words to be frequent: this would mean that the first three past-tense forms in each table above (viz. the irregulars had/said/did and the regulars looked/asked/wanned) would be designated as frequent forms, and the last three as infrequent forms. What you do next is see whether JC performs better overall on frequent than infrequent irregulars, and better overall on frequent than infrequent regulars. To do this for the irregulars in table (15), you add up how often he produces the correct past tense form of frequent irregulars (= 6 times, comprising 5 correct tokens of said and 1 correct token of did), multiply this by 100, and divide the resulting figure by the number of times he uses frequent irregulars in past tense contexts (= 13, comprising 3 obligatory contexts where adults would have used the past tense form had, 9 obligatory contexts for said and 1 for did). For the tiny subset of data in table (15), this would give us a percent correct suppliance rate for frequent irregulars of 46% (i.e. 6 x 100 ÷ 13). Doing a parallel calculation for the infrequent irregular pasts in table (15) shows that JC produces 1 correct token of bit, 2 correct tokens of forgot and that there is 1 obligatory context for the past tense form bit, 7 for ate and 2 for forgot: his percent suppliance rate for the correct irregular pasts is thus 30% (3 x 100 ÷ 10). To see whether JC performs better on the frequent regular pasts than on the infrequent ones, we do a similar set of calculations in relation to table (16). He uses the 3 most frequent verbs 6 times in past tense contexts, and produces only 2 correct past tense forms, so his percent suppliance of the correct past tense form for frequent regular pasts is 33% (i.e. 2 x 100 ÷ 6). He uses the 3 least frequent verbs 3 times in past tense contexts, and produces only 1 correct past tense form, so his percent suppliance of the correct past tense form for frequent regular pasts is again 33% (i.e. 1 x 100 ÷ 3). So, doing the relevant calculations on the verbs in the tables in (15) and (16) would lead us to the conclusion that we have evidence of a frequency effect for irregular pasts (in that he performs substantially better on frequent than infrequent irregular pasts), but not for regular pasts (where he performs at the same level on both frequent and infrequent regular pasts). But bear in mind two things. Firstly, these conclusions are based on partial tables which contain only a small number of the verb forms used by JC in past tense contexts: your own conclusions must be based on complete tables which list all the verb-forms used by JC in past tense contexts. Secondly, even complete tables may yield insufficient data for you to draw any firm conclusions about whether there is (or isn’t) a frequency effect – especially where any effect you find is marginal (e.g. a difference of only a handful of percentage points). 192 Wanned is the past/perfect/passive form of WANT in colloquial American English, the final t of the stem being dropped in rapid speech in forms like wanna (= want to) and wanned (= wanted). 69 If you want to be particularly thorough, you could also try testing for a second kind of frequency effect (mentioned in Gopnik and Crago 1991). You will note that JC performs particularly badly on some verbs: e.g. he uses the bare form eat on 7 occasions in contexts where adults require the past form ate, and not once does he produce the correct past tense form ate. A question which you might ask is whether this kind of performance is associated with verbs whose bare form (e.g. eat) is more frequent than its past form (e.g. ate) in adult English (using the raw frequency figures in Carroll’s dictionary193). To do this, you will need to draw up a (complete version of) the (partial) table below for irregular verbs used in past-tense contexts by JC): (17) Table of frequency of adult irregular bare/past forms, and JC’s suppliance of past Raw frequency of past form Raw frequency of bare form JC’s suppliance of past said = 15309 say = 3916 5/9 brought = 1357 bring = 1016 0/1 ate = 440 eat = 1616 0/7 saw = 2900 see = 8518 1/5 You can then see whether JC performs better at marking past tense on verbs on irregular verbs whose past tense form is more frequent than its bare form. For example, if we take the first two verbs in the table in (17), we see that both of them have past tense forms which are more frequent than their bare forms, and that JC’s mean suppliance rate for the past tense forms of these two verbs is 5/10 (50%). By contrast, if we take the last two verbs on the list, we see that their past forms are less frequent than their bare forms, and that JC’s mean suppliance rate for these two items is only 1/12 (8%). If the results we obtain from the partial table in (17) were replicated for the corresponding full table which you need to draw up for yourself (if you decide to test for this kind of frequency effect), this would mean that we do find the kind of frequency effect which might be expected if irregulars are learned by memorisation. Now, if Gopnik and Crago are right in claiming that SLI children have a genetic rule deficit and so have to memorise regulars as well, we might expect to find a parallel frequency effect with regulars – and to see whether this is the case, you can draw up another table like that in (17) for regular bare/past forms. If we found such a frequency effect with irregular pasts but not regular pasts, this would lead us to the conclusion that Gopnik and Crago are wrong, and that irregulars pasts are memorised foms but regulars are rule-derived forms. 2.5 Testing the Agreement Deficit model If one of the models of SLI which you have chosen to work on is the Agreement Deficit model, you will need to compare how well JC peforms on past tense verbs (these not being overtly inflected for agreement) with how well he performs on third person singular present tense forms (these being overtly inflected for agreement). Hence, you will also need to calculate JC’s suppliance rate for regular and irregular third person singular present tense forms. You can find detailed guidance on how to do this in §2.4 and §2.5 of the next chapter. 2.6 Testing the ATOM model The ATOM model claims that SLI children sporadically mark tense and agreement in obligatory contexts, and that nominative subjects are found when agreement is marked, and accusative subjects when it is not marked. Hence, if ATOM is one of the models you have chosen to work on, one of thin things you will need to calculate is how frequently JC marks tense in past tense contexts. In order to do this, you can 193 Carroll gives the following figures for adult frequency (per million words) of bare forms of relevant irregular verbs: have = 22337; do = 12695; make = 8333; come = 4676; go = 5388; find = 6916; see = 8518; get = 5700; take = 4089; put = 3942; give = 3366; say = 3916; eat = 1616; cut = 1757; bring = 1016; fall = 824; sleep = 717; catch = 679; drive = 543; hurt = 457; drink = 347; forget = 314; lose = 268; bite = 172; wake = 113. Carroll also gives the following adult frequency figures (per million words) for the bare forms of relevant regular verbs: use = 7009; look = 4933; want = 2655; show = 2734; play = 2113; try = 1958; talk = 1133; ask = 900; drop = 433; die = 360; jump = 356; laugh = 287; cook = 265; melt = 100; knock = 85; grab = 73; scare = 55; shovel = 60; burn = 43; dump = 33; pinch = 30. 70 make use of the raw frequency figures in (your complete version of) the table in (8) above, repeated in (18) below: (15) Raw frequency of verb-forms used by JC in past tense contexts (repeated from (9) above) Type Verb A: correct form B: bare form C: other form 1. regular DUMP dump = 3 1. regular SCARE scared = 1 scare = 3 1. regular SHOVEL shovelled = 4 2. novel JUMPOVER jumpovered = 1 3. mixed BURN burn = 1 4. Irregular DRIVE drived = 1 4. Irregular EAT eat = 7 4. Irregular LOSE lost = 3 4. Irregular TAKE took = 1 take = 2 taked = 1 5. Invariable irregular CUT cut = 2 Which of the verb forms in this table are (and are not) marked for past tense? Well, the correct adult past tense forms which appear in column A are clearly marked for past tense – though we have to exclude invariable irregulars like CUT, since if a child uses the verb form cut in a past tense context, we have no way of knowing whether he is using a past tense form or a bare infinitive form (since these two forms are identical for verbs like CUT): hence, our calculations must be based on verbs with a distinctive past tense form (i.e. one distinct from the corresponding bare/infinitive form). This means we include only verbs of types 1-4, and exclude verbs of type 5. A second class of verb forms which are clearly marked for past tense are over-regularised forms like drived and taked which appear in column C. By contrast, the bare/infinitive forms in column B appear to be tenseless (i.e. not inflected for tense). Accordingly, we can calculate how frequently JC marks tense in past tense contexts by doing the following simple calculation: (19) % marking of past tense on verbs = with a distinctive past form no. of tokens of verb-forms marked for past x 100 no. of obligatory contexts for past tense forms Since verbs of types 1-4 have a distinctive past form (but not verbs of type 5), and since the forms in columns A and C are marked for past tense, we can calculate the number of tokens of verb-forms distinctively marked for past tense by adding up the number of tokens in columns 1A, 2A, 3A, 4A, 1C, 2C, 3C, and 4C: for the table in (15), the total comes to 12 (made up of 1 token of scared, 4 of shoveled, 1 of jumpovered, 3 of lost, 1 of took, 1 of drived, 1 of taked). Then we multiply this figure of 12 by 100, giving us 1,200. We then need to calculate the number of obligatory contexts for past tense forms of verbs with a distinctive past form, and we can do this by adding up the number of tokens in columns 1A, 2A, 3A, 4A, 1B, 2B, 3B, 4B, 1C, 2C, 3C and 4C together: for the table in (15), the relevant total comes to 28 (made up of 1 token of scared, 4 of shoveled, 1 of jumpovered, 3 of lost, 1 of took, 1 of drived, 1 of taked, 3 of dump, 3 of scare, 1 of burn, 7 of eat, and 2 of take). We then divide our top-line figure of 1,200 by our bottom-line figure of 28, and arrive at a score of 43% marking of past tense (on verbs with a distinctive past tense form) in obligatory contexts. Of course, I’ve computed this figure from the partial table in (8/18): you need to compute your figure from a complete counterpart of the relevant table. A second key claim made by ATOM is that SLI children have problems in marking on agreement in past tense verbs, and that failure to mark agreement leads to the use of default accusative subjects. Because past tense verbs don’t overtly inflect for agreement in English (with the exception of the irregular auxiliary/copula forms was/were), you can’t tell directly whether a past tense form is marked for agreement – e.g. by looking at whether it carries a third person singular -s inflection. But you can look at the case assigned to its subject. On the ATOM assumption that a nominative subject occurs with an agreeing (auxiliary or non-auxiliary) verb and a default accusative subjects with an agreementless verb, we would expect to find that (in past tense contexts) children alternate between nominative and accusative subjects (irrespective of whether they use past tense or bare forms – see the discussion in §1.6. Hence, we 71 need to look at the frequency with which JC uses nominative and accusative subjects in past tense contexts. Of course, we can only do this for verbs which have subjects which are unambiguously marked as either nominative or accusative. Hence, we have to exclude verbs with subjects like Daddy, you or it because they have a common nominative-accusative form, and so there is no way of telling whether they are nominative or accusative. In other words, we have to look at sentences with I/me, we/us, he/him, she/her, or they/them subjects. The first step, then, is to go back to the list of sentences in (8) above, and use it to create a sub-list like that below which shows the sentences produced by JC in past contexts with unambiguously nominative subjects like I/we/he and those with unambiguously accusative subjects like me/her194/them: (20) List of sentences with nominative or accusative subjects used by JC in past-tense contexts A: Nominative subject B: Accusative subject 198. Long time ago I have a big eye 103. Me just jumpovered it 236. I never saw one of these stove 327. Then me said ‘Oh!’ 321. Long time ago, I go camp and hiking… 328. Then me take it xxx 229. We see clown at...umm... 283. And we scare her 268. Her make it for Ms Peggy a long time ago 277. Her give me dad a lobster 314. Then her got hurt 126. He shoveled him truck 127 And then he dump it 132. And then he drived away 300. He jumped out 301. He bit me 316. He try to eat me up 379. He cut me 231. Them have a party 366. But them cut my hair real tiny Note that the list I have drawn up in (20) is only a partial list (for illustrative purposes) based on a randomly chosen subset of the relevant example sentences from the list in (7). Your own list has to contain all the sentences produced by JC in past tense contexts which have unambiguously nominative or accusative subjects195. Include your own complete version of the list in (20) as an Appendix to your project – don’t include it in the main text (because it interrupts the flow of the text). Once you’ve drawn up your own counterpart of the list in (20), you can use it to calculate the percentage of nominative subjects used by JC in past tense contexts, in the manner shown below: (21) % of nominative subjects in past tense contexts = no. of tokens of nominative subjects x 100 no. of tokens of nominative + accusative subjects If we did this calculation for the (partial) list in (20), we first need to count the number of tokens of nominative subjects in column A: this is 12 (made up of 3 tokens of I, 2 of we and 7 of he). We then multiply this total of 12 by 100, giving 1,200. We then add up the number of tokens of nominative and accusative subjects in columns A and B: this is 20 (made up of 3 tokens of I, 2 of we, 7 of he, 3 of me, 3 of her and 2 of them). So, we divide our top-line figure of 1,200 by our bottom-line figure of 20, and arrive at the conclusion that 60% of the subjects used by JC in past tense contexts are nominative. If the use of a nominative subject is an indication of agreement being marked on the associated verb (as ATOM claims), then this means that JC marks agreement on 60% of verbs used in past tense contexts. Her could in principle be genitive, but given that JC doesn’t otherwise use genitive subjects (but does use a lot of accusative subjects), it is far more likely to be accusative. 195 Only look at cases where the subject is a pronoun on its own, not at cases where the subject comprises a pronoun modifying a noun – hence not at me mommy in utterance 337 Me mommy show me to make Easter eggs. This is because the pronoun me here is not the subject of the sentence: rather, mommy is the subject, and me is a possessive modifier of mommy. 194 72 A prediction of the ATOM model which you can test in relation to the list of sentences in your complete version of table (20) is that SLI children will alternate between producing nominative and accusative subjects both with bare verbs used in past tense contexts and with verbs overtly marked for past tense. To give you an idea of what to do, in the table below, I have listed the raw frequency with which JC uses unambiguously nominative and accusative subjects in past tense contexts in utterances 5-132: (22) Frequency of JC’s unambiguously case-marked pronoun subjects in past tense contexts A: nominative+past B: nominative+infinitive C: accusative+past D: accusative+infinitive he = 4 he = 7 me = 5 me = 4 2.6 Summary of research results You should end your chapter with a brief section recapitulating your main research results. 3. Analysis of research results (around 35% of your overall study) 3.1 Introduction Begin by saying that what you are aiming to do in this section/chapter is evaluate the extent to which the research findings which you obtained in the previous chapter are consistent (or inconsistent) with the research hypotheses which you outlined in chapter 1, and (more generally) with the particular models of SLI which you are aiming to test. Since you are ultimately concerned with evaluating a range of theories of SLI, perhaps the best way of organising the material in this chapter into sections is by theory – e.g. discussing the extent to which your research findings are compatible with the Perceptual Deficit model in section 3.2, with the Rule Deficit model in section 3.3, with the Agreement Deficit model in section 3.4 and with the ATOM model in section 3.5. 3.2 Evaluation of the Perceptual Deficit model Begin by reminding the reader briefly (in one or two sentences) of the general assumptions underlying the model, and the key prediction it makes about past tense – viz. that SLI children should perform better on past tense forms marked by the use of a vowel than on those marked by use of a consonant. Discuss the findings you yourself arrived at for the three types of past tense verb-form in (your complete version of) the lists in (11), (12) and (13), and whether these are compatible with Leonard’s claim. If you found evidence of some perceptual effect, was the effect strong (e.g. JC performed twice as well on some forms than others), or weak (e.g. JC performed marginally better on some forms than other)196. If weak, could they be attributable to simply not having enough data to make reliable calculations? And if you find no evidence of perceptual effects of any kind, could this be because such effects do not exist (and the Perceptual Deficit model is thereby falsified), or because you simply don’t have enough data to test properly for such effects? 3.3 Evaluation of the Rule Deficit model In section 3.4, you might evaluate Gopnik and Crago’s Rule Deficit model. Begin by providing a brief outline of the general assumptions made in the model, and the specific predictions it makes about past tense marking. The main research findings which are going to be relevant here are whether JC uses overregularised forms (though pay heed to the footnote in this chapter about such forms), and whether you have found the expected frequency effect for regular as well as irregular pasts. If you don’t find frequency effects, do you conclude (i) that no such effects exist, or (ii) that they may well exist but you probably don’t have enough data to test for them (or indeed that a frequency dictionary based on written English is a poor reflection of the speech input a child receives)? What if we modified the Rule Deficit model so as to claim not that SLI children fail to acquire any regular morphological rules, but rather that (at a given 196 Technically, what we should be looking for here is whether any effects you find are statistically significant or not: but since this course is not designed to provide you with training in statistics, you need not be concerned with this. 73 stage of development) they may have acquired some but not all regular rules, and that even the rules they have acquired may be applied sporadically (with better established rules being applied more frequently than less well established rules)? 3.5 Evaluation of the Agreement Deficit model Begin by providing a brief outline of its key prediction, namely that SLI children will perform well on past tense forms because they only inflect for an interpretable tense feature, but badly on third person singular present tense forms (because these also inflect for uninterpretable agreement features). Look first of all at whether (as predicted) JC does well on regular past tense {d}, but badly on regular third-person-singular present-tense {s}. Then look at whether he does well on irregular past tense forms, and badly on irregular present-tense forms. If your findings don’t quite match the predictions of the model, consider why this might be: e.g. maybe tense is a cognitively complex concept (Reichenbach arguing that tense involves a complex relation between three points in time, namely speech time, event time and reference time); maybe uninterpretable features slow down (rather than prevent) acquisition of particular morphemes, so that high-frequency items will be acquired even if encoding uninterpretable features; maybe when children use a bare irregular form like give in the past tense, they wrongly assume that it is the past tense form of GIVE, and have learned that GIVE is irregular in respect of not taking the regular past tense d-suffix (unlike TELL whose past tense is told), but not that the vowel in the stem changes from |I| to |eI| in the past tense. 3.6 Evaluation of the ATOM model Begin by providing a brief outline of its core assumptions and what it predicts will happen in past tense contexts – namely that we will find four types of structure: nominative+past forms like He played with me yesterday; accusative+past forms like Him played with me yesterday; nominative+infinitive forms like He play with me yesterday, and accusative+infinitive forms like Him play with me yesterday. The obvious question for you to answer in relation to the data in your version of the table in (20) is whether you find evidence that JC produces all four types of structure or not. You might want to consider possible problems with ATOM – e.g. its abstractness and circularity, its failure to make precise predictions about how often tense and agreement are marked, its failure to account for why children might be better at marking nominative case on some pronouns than others (e.g. you might want to compare how well JC fares on e.g. he subjects compared with I subjects). Chapter 4. Summary and Conclusions (about 15% of your overall study) 4.1 Summary of research hypotheses Begin this chapter with a section in which you provide a brief summary of the models of SLI and research hypotheses which you outlined in chapter 1. 4.2 Summary of research findings In this section, briefly summarise the main research findings you obtained in chapter 2. 4.3 Summary of evaluations In this section, provide a brief summary of your evaluation (in chapter 3) of the relative strengths and weaknesses of each of the theories of SLI you are testing, viewed from the perspective of how well they account for your own research findings. 4.4 Overall conclusions In this (the most important) section of your chapter, you need to give your considered final verdict on which of the models you have looked at best accounts for your own research findings. If a particular model doesn’t account for (some of) your findings, can it be modified in some way which would make it compatible with your findings? If not, and if there is no one model of SLI which accounts for all your research findings, does this take you towards a composite model which sees SLI as involving multiple impairments, rather than a single type of impairment? (See my suggestions for what such a composite model might look like in the section on chapter 4 in the next chapter.) To what extent would such a 74 composite model be able to account for your research findings about JC’s past tense marking? Be particularly circumspect with your conclusions: these are usually the weakest point in student work, and a weak conclusion will devalue your overall project. Avoid excessively general, unsubstantiated claims. 5. Appendices After your four main chapters, include as an Appendix any lists of sentences which provide the raw data from which you computed the figures for various tables included in the main body of your project, and any tables from which you have computed suppliance rates (and any other figures you use). 6. List of references After any Appendices, include a list of works (arranged alphabetically by author and date) which you have cited in your project, using the standard author-date system described in the departmental handbook. 75 9: Empirical study II: Acquisition of English s-forms In this chapter, we look at how to use the JC corpus to undertake an empirical study of The acquisition of English s-forms by a 4-year-old child with SLI. Your study might be organised into sections and subsections as follows. 1. Background (about 25% of your overall study) 1.1 Introduction Give brief details (in a paragraph) on the kind of developmental disorder which SLI involves (summarised on p.4 of this book: see Bishop (1997), Leonard (1998), and the collection of papers in Bishop and Leonard (2000) and Levy and Schaeffer (2003) for more detailed discussion of diagnostic criteria for SLI), pointing out that various aspects of grammar are reported to be impaired in SLI children, including the ability to produce inflected forms. Then go on to say that there are a wide range of different models of SLI which seek to account for the nature of the grammatical impairment in SLI children, and for the purposes of the present study you are going to examine a subset of these (e.g. the Perceptual Deficit, Rule Deficit, Agreement Deficit and ATOM models). Your aim is to do a small-scale empirical study designed to evaluate each of the models, by looking at the production of three types of s-form in obligatory contexts by a four-year-old American boy with SLI, known as JC. Provide brief details of JC’s background (which you can find at the beginning of chapter 13). The three types of s-form you are going to look at are (i) noun plural -s, (ii) genitive ’s, and (iii) third person singular present-tense -s. You’re going to begin by outlining the morphophonology of s-forms in English in the next section 1.2 Outline of the morphophonology of s-forms in English In this section, you need to provide a brief account of the morphophonology of each of the three s-forms you are studying. The dual mechanism model of the acquisition of morphology (outlined e.g. in Pinker and Prince 1988 and Pinker 1991) maintains that irregular forms are memorised forms which are stored/listed in the mental lexicon, whereas regular forms are computed or derived via application of morphological rules like those sketched informally in (1-3) below (with morphemes enclosed in curly brackets, by convention): (1) A regular verb carries the suffix {s} if third person singular present {d} if past, perfect or passive {ing} if progressive or gerund {ø} otherwise (2) A regular noun carries the suffix: {s} if plural {ø} otherwise (3) A noun expression197 carries the suffix {s} if genitive {ø} otherwise The precise phonological form which a morpheme is given in a particular structure is determined by (morphophonological) spellout rules like (4) below: The informal term noun expression is used to denote an expression which comprises or contains a noun – e.g. an expression such as John or the girl next door. Note that genitive ’s is attached to the end of the last word in the relevant noun expression, as in the girl next door’s. 197 76 (4) {s} is spelled out as: |Iz| when attached to a form ending in a sibilant consonant (e.g. passes, buzzes, catches, cages, pushes, camouflages) |z| when attached to a form ending in another voiced segment198 (e.g. calls, robs, bags, grows, pays) |s| when attached to a form ending in another voiceless segment199 (e.g. cuts, locks, breaks, rocks) |ø| when attached to a form already ending in {s} (e.g. the boys’ school, where genitive {s} has a null spellout by virtue of being attached to a noun boys carrying plural {s}) So, for example, the lexical entry (i.e. entry in the dictionary) for the regular noun CAT will contain simply the stem form cat: its plural form will be generated by adding the suffix {s} to the stem form in accordance with the first line of rule (2), so deriving cats; this {s} morpheme will be spelled out as |s| in accordance with the third line of rule (4), so that the word is pronounced |kats|. The singular form of CAT will be generated by adding the null suffix {ø} in accordance with the second line of rule (2), generating cat-ø. By contrast, the lexical entry for the irregular noun MOUSE will contain not only the singular form mouse but also the irregular plural form mice: the presence of the irregular plural form mice in the lexicon will then block application of the regular plural formation rule in (2), so accounting for why we don’t find *mouses as the plural of mouse. Similarly, the lexical entry for a regular verb like PLAY will specify simply that it has the stem form play, and the morphological rules in (1) will determine that its third person singular present tense form is derived by adding {s} to the stem form, its past tense and perfect/passive participle forms by adding {d}, its progressive participle and gerund forms by adding {ing}, and all other forms by adding a null affix {ø}. By contrast, the lexical entry for an irregular verb like GO will specify that it has the stem form go, the irregular perfect participle form gone and the irregular past tense form went; it will follow from this that its (regular) third person singular present tense form is derived by adding {s} to the stem form (giving goes) in accordance with the rule (1), its (regular) progressive participle form is derived by adding {ing} to the stem form (giving going), and its other forms are derived by adding the null affix -ø to the stem form (giving go+ø) in accordance with (1v). Given that the dual mechanism account maintains that regular forms are rule-generated and irregulars are stored, it is important to be able to differentiate between regular and irregular forms. This is not an issue which arises with genitive ’s, since there are no irregular genitive s-forms for noun expressions in English (though of course there are irregular genitive pronouns like my/our/your/her/their etc.). In the case of plural nouns, the difference between regular plural forms like cats and irregulars like mice is relatively clearcut. But the difference between regular and irregular forms is less clearcut in the case of third person singular present-tense (3SgPres) s-forms. While the 3SgPres forms of the vast majority of verbs is entirely regular in English (as with e.g. helps, works, sleeps, cries etc.), there are a handful of 3SgPres forms which are potentially irregular – such as says, has, does and is. The irregularity of the verb SAY lies in the fact that although its stem form is |seI| in forms like say/saying, it has the irregular stem-form |se| in the inflected forms says and said. The forms has and does can be used either as main verbs (e.g. in He has a flat in town or He does a lot of work for charity) or as auxiliaries (e.g. in Has he finished the assigment? or Does he take sugar?), whereas the form is always functions as an auxiliary (and hence has the contracted negative form isn’t and can undergo inversion in questions like Is it raining?). What’s irregular about the verb HAVE is that it has the stem form hav- in forms like have/having, but the contracted stem form ha- in the forms has and had. When used as an auxiliary, HAVE is even more irregular, in that its vowel can be reduced to schwa (so that in Has he left? the auxiliary has can be pronounced |əz|, for example), and it can even lose its vowel entirely (e.g. in He’s left). The irregularity of the 3SgPres form does lies in the fact that it is derived by adding {s} not to the regular stem do- |du:|, but rather to the irregular stem doe- |d|, yielding does |dz|. In its use as an auxiliary, the vowel can be reduced to schwa, so that in Does Jim like her? the auxiliary does can be pronounced |dəz|. Indeed, does can be contracted down to ’s in certain Since all vowels are voiced, this means ‘when attached to a stem ending in a vowel, or a voiced non-sibilant consonant’. 199 In other words ‘when attached to a voiceless consonant which is not a sibilant’. 198 77 contexts (as in What’s he like for breakfast? = What does he like for breakfast?). An additional complication to note is that in many varieties of (esp. American) English, it has the irregular 3SgPres negative form don’t (as in the typical pop-song lament She don’t love me no more). As for the 3SgPres form is, this is a suppletive form which seems to be unrelated to other forms of BE, and hence completely irregular. It too has a contracted form ’s (e.g. in He’s lazy). Given the irregularity of says/has/does/is, it seems likely that these are stored/memorised forms rather than rule-derived forms. Empirical research is about testing research hypotheses, so in sections 1.3-1.6, you should provide a short summary of the overall claims made by each of the models of SLI which you have decided to evaluate, and then go on to say what specific prediction each makes about how well SLI children would be expected to perform on each of the four types of s-form which you are looking at. 1.3 Outline of the Perceptual Deficit model of SLI In this section, you should provide a brief outline of the Perceptual Deficit model and note that its key claim is that consonantal inflections pose more perceptual problems for SLI children than vocalic inflections, and so (on the face of it) appears to predict that SLI children will perform badly on all s-forms (because they are consonantal). But things are not quite as straightforward as that, for two reasons. Firstly, all three s-forms that you are concerned with here have the three overt allomorphs |s|, |z| and |Iz| as seen in section 1.2, and we might therefore expect SLI children to perform better on the last of these three because it contains a vowel: in addition, genitive ’s has an additional null allomorph (used e.g. with nouns which end in regular plural -s, as in boys’ toys). 1.4 Outline of the Rule Deficit model of SLI In this section, you should outline the Rule Deficit model, and note that it claims that SLI children have a genetic rule-deficit which makes it impossible for them to acquire any regular morphological rules. They are therefore predicted to be unable to acquire the noun plural s-rule which specifies that a regular noun like cat is pluralized by adding the suffix {s} to it, so forming cats: likewise, they are predicted to be unable to acquire the genitive s-rule which specifies that a noun expression like Daddy or the girl next door which is marked as carrying genitive case has the affix {s} added to the last word of the expression, so forming Daddy’s or the girl next door’s; similarly, they are predicted to be unable to acquire the present tense s-rule which specifies that a regular verb has the suffix {s} attached to it if it is a third person singular present tense form. It might therefore seem at first sight that the prediction made by the Rule Deficit model is that SLI children will always use bare forms in contexts where adults use s-forms (and hence will say e.g. two car instead of two cars, Daddy car instead of Daddy’s car, and Daddy play with me instead of Daddy plays with me). But things are not quite as simple as that, because Gopnik and Crago maintain that although SLI children acquire regular morphological rules, they can memorise inflected forms (both regular and irregular alike), though cannot produce novel or over-regularised s-forms. Since memorisation of a given form requires extensive exposure to the relevant form, we therefore expect to find a frequency effect (viz. that the more often a child hears a given s-form, the more often the child is likely to produce it correctly). This leads to the following predictions about how well SLI children fare on s-forms. In the case of plural s-forms like eyes and 3Sg present-tense verbs forms (both regular forms like plays and irregulars like is/has/does), the prediction is that the child should perform well on highfrequency forms (whether regular or irregular), and poorly on low-frequency forms (whether regular or irregular) – and not produce novel or over-regularised forms. For genitive s-forms, the prediction is rather more complex. If we assume that a child can memorise inflected words but not inflected phrases (because there are an infinite set of possible phrases – cf. the man’s, the tall man’s, the tall handsome man’s, the talk dark handsome man’s etc. – and it is in principle impossible to memorise an infinite set), we might expect to find that SLI children can memorise genitive forms of high frequency individual words like Daddy’s but not genitive forms of phrases like the man’s: if so, we might expect an SLI child to say Daddy’s car but the man car. A child who has acquired the genitive s-rule might also be expected to produce over-regularised genitive pronouns like e.g. I’s or me’s in place of my/mine. 78 1.5 Outline of the Agreement Deficit model of SLI In this section, you should outline the Agreement Deficit model, and note that it claims that SLI children have particular problems with acquiring uninterpretable agreement features, but not with other features (e.g. not with interpretable tense features, or uninterpretable case features). They should therefore be good at producing those s-forms which encode interpretable features: if we assume that plural nouns like dogs carry an interpretable number feature (marking the presence of more than one dog), we should expect that SLI children will perform well on plural s-forms of nouns. By contrast, we should expect SLI children to be bad at third person singular present tense s-forms of verbs, since these carry uninterpretable agreement features. Given that Clahsen, Bartke and Göller (1997) claim that it is specifically uninterpretable agreement features which cause problems for SLI children, and not e.g. uninterpretable case features200, we should expect SLI children to perform well on genitive ’s. 1.6 Outline of the Agreement and Tense Omission (ATOM) model of SLI In this section, outline the ATOM model, and note that it claims that in finite contexts (i.e. in contexts where adults use an auxiliary or main verb marked for tense and agreement), SLI children who are at the EOI/Extended Optional Infinitives stage (generally, children under 7-8 years of age) sometimes fail to mark tense and/or agreement, and that this affects the case assigned to the subject (in that a subject of an agreeing verb is nominative, whereas the subject of an agreementless verb is assigned default accusative case). The predictions made by ATOM are clearcut in relation to contexts for s-inflected verb-forms. In a context where an adult would use a present-tense main verb like plays (e.g. in reply to a question like What does Daddy do when he comes home?), we’d expect an SLI child to produce four different kinds of structure. One would be a structure marking both tense and agreement: if the child has acquired the set of verb inflections in (1), we’d then expect such a child to use the s-form plays, and to assigns its subject nominative case (because agreement is marked), so resulting in He plays with me. A second would be a structure in which agreement but not tense is marked; since (1) specifies that a null affix -ø is used by default when either tense or agreement (or both) are not marked, and since ATOM assumes that nominative subjects are used when agreement is marked, this will result in structures like He play with me. A third is a structure in which tense but not agreement is marked; since (1) tells us that a default null affix -ø is used when either tense or agreement (or both) are not marked, and since ATOM maintains that accusative subjects are used when agreement is not marked, this will result in a structure like Him play with me. The fourth type of structure we expect to find is one in which neither tense nor agreement is marked; since (1) says that a default null affix -ø is used when either tense or agreement (or both) are not marked, and since ATOM claims that default accusative subjects are used when agreement is not marked, this will again result in a structure like Him play with me201. ATOM also makes predictions about what SLI children will do in contexts where adults would use an irregular (non-modal) auxiliary like is/has/does (or their contracted variants). For example, consider what an SLI child would be expected to reply to question like What’s Daddy doing?. If both tense and agreement are marked, the child will reply He’s snoring. If agreement but not tense is marked, the child will say He snoring (because ATOM claims that BE/HAVE/DO when used as auxiliaries are null whenever underspecified for tense and/or agreement, but the presence of agreement will trigger nominative case assignment). If tense is marked without agreement (or indeed if neither tense nor agreement is marked), the child will say Him snoring. The predictions made by ATOM in the case of plural nouns would seem to be that no problems are expected. The implication of the ATOM claim that SLI children have problems in marking agreement features is presumably that SLI children will not have problems in marking number on nouns, but will 200 Recall that CBG reported the English SLI children in their study having 100% correct case-marking. The picture would become more complicated for an SLI child who acquired the tense feature associated with the affix -s but not the agreement features, and so treated -s as marking present tense only. Such a child would (under ATOM assumptions) be predicted to use present-tense s-forms with subjects of any person or number, and with both nominative and accusative subjects – for reasons which should be clear. 201 79 have problems in marking number on verbs which agree with those nouns202. So, if we suppose that the number feature carried by a plural noun like dogs is not an agreement feature203, then since ATOM specifies that only tense and agreement features pose problems for SLI children, the implication is presumably that SLI children like JC should fare well on plural nouns (both regular and irregular). The predictions made by ATOM in relation to genitive s-forms are difficult to work out, because Wexler, Schütze and Rice (1998) do not talk about genitive case-marking in any detail. However, if (as they claim: 1998, p.323) ‘Case is a reflection of structural grammatical relations’ and if agreement is the core structural relation in syntax, then it would seem reasonable to suppose that genitive case is assigned to a nominal via some form of agreement. Since we find a possessor agreeing with a possessum (= possessed entity) in person and number in languages like French (e.g. in structures like ma maison ‘my house’ where the possessor ma ‘my’ is feminine singular in form because it agrees with the feminine singular possessum maison ‘house’), we could assume that a possessor is assigned genitive case when it agrees (invisibly, in languages like English) with the possessum204. What ATOM would then predict is that if possessor agreement is marked, the possessor will be assigned genitive case (so giving rise to genitive-possesor structures such as Daddy’s car and my car etc.); but if possessor agreement is not marked, the possessor will instead be spelled out in the default (accusative) form, so giving rise to accusative-possessor forms such as Daddy car and me car. Of course, since possessor-agreement is not overtly visible in English, any such analysis is of necessity abstract in character. 1.7 Summary of research hypotheses In section 1.7, you should summarise the predictions made by each of your chosen accounts of SLI, and outline the research hypotheses that you are setting out to test. An important observation to make is that the predictions made by individual models can be skewed by lexical gaps. For example, if a child has not acquired a particular affix or a particular inflected form, then it is clear that the child will not use the relevant affix/form – even if particular theories of SLI predict that it would be used by children who have acquired it in certain contexts. 2: Research results (about 25% of your overall study) 2.1 Introduction Begin this section with an introduction, saying that you are setting out to test the research hypotheses that you outlined in section 1.7 by looking at the types of structure produced by JC in contexts where adults would use s-forms. You are going to look at plural s-forms in section 2.2, genitive s-forms in section 2.3, and present-tense s-forms of main verbs in section 2.4, and present-tense s-forms of auxiliaries in section 2.5 (auxiliaries and main verbs being dealt with in separate sections because of the differences ATOM predicts about in how SLI children treat s-inflected auxilaries and s-inflected main verbs). 2.2 Research results for plural s-forms of nouns Begin this section by saying that you drew up a list of sentences from the JC corpus which represent obligatory contexts for plural s-forms – and include this list in the Appendix to your project. In order to help you with this task, below I have drawn up a list of sentences produced by JC containing (italicised) nouns used in (what seem to me to be) plural contexts (i.e. contexts where adults would have used a plural s-form). You will see that I have also included the plural N-pronoun (i.e. pronominal noun) ones, because 202 In more technical terms, this would amount to claiming that SLI children have problems in marking number when it is an uninterpretable feature on verbs, but not when it is an interpretable feature on nouns. 203 This is far from obvious in relation to expressions like two dogs, where it might be argued that the noun dogs acquires its plural number feature via a form of agreement (traditionally called Concord) with the plural numeral quantifier two. 204 For a variety of technical reasons which it would not be appropriate to go into here, a more principled analysis would be to suppose that genitive case is assigned to a possessor via agreement with an abstract functional head (perhaps with a null determiner of some kind, as suggested in Abney 1987). 80 it forms its plural by use of the same s-affix as regular plural nouns like dogs. Where the structure of the relevant utterance is unclear, I’ve added the presumed adult counterpart in parentheses. (5) List of (italicized) s-forms of nouns used by JC in potential plural contexts 11 Why him don’t have eyes? 44 When him crack tiny pieces up, and then put xxx. 92 I make some peppers 109 And put buns on it, and ketchup. 156 He have he hats on. 165 (Th)ey are straps. 183 He can fly cause he got these wings. 208 An owl did this with he eyes. 227 I wanna play some games. 236 I never saw one of these stove. 237 Me making hot dogs. 250 I have tea at boy scout (= ‘at the boy scouts’). 273 And then, you could get lots fish in there. 277 Her give me dad a lobster, a two lobster (?= ‘a pair of lobsters’). 279 Forgot to take them eyes out. 288 No, you can’t eat eyes 297 Two lobsters. 299 Lobsters don’t go there. 307 Lobsters live in an ocean. 333 We making books. 336 Easter eggs. 337 Me mommy show me to make Easter eggs. 346 My dad make eggs, but mushy eggs. 353 Me mom hold in him hands. 356 He put in a box with lots different and jelly bean. 358 Then mom and kids find easter eggs. 362 I need ten stickers. 369 We got some new pictures. 371 I know these ones. 373 Them both have pinchers205. 374 Why them both have pinchers? 375 Both got legs You can use the data in this list to draw up a frequency table which shows the raw frequency of individual s-forms produced by JC in obligatory plural contexts. The partial table in (6) below gives you an idea of what your frequency table might look like (with numerals indicating the number of times JC used the relevant word in plural contexts): (6) Raw frequency of noun-forms used by JC in plural contexts Noun A: correct form B: bare form EGG eggs = 5 LOBSTER lobsters = 3 lobster = 1 C: other form Having drawn up (your own complete version of) a frequency table like that in (6), you can then use the data in the table to calculate JC’s percent suppliance of plural s-forms in obligatory contexts, in the manner shown below: (7) % suppliance of plural s-forms of nouns in obligatory contexts = no. of tokens of correct plural s-forms of nouns x 100 no. of obligatory contexts for plural s-forms of nouns If we do this calculation for the (small subset) of data in table (6), what we do is first of all add up the number of tokens of correct s-forms in column A: this comes to 8 (viz. 5 tokens of eggs and 3 of lobsters). We then multiply this total of 8 by 100, giving us a top-line figure of 800. We calculate the number of obligatory contexts for plural s-forms of nouns by adding up the number of tokens of correct and incorrect noun-forms in columns A, B and C: this comes to 9 (viz. 5 tokens of eggs, 3 of lobsters, and 1 of lobster). We then divide our top-line total of 800 by our bottom-line total of 9, giving us a figure of 89% supplinace of plural -s on nouns in obligatory contexts206. Of course, this figure is only based on a partial set of data: your own score must be based on the complete set of data in (5), and may be somewhat different from this. 2.3 Research results for genitive s-forms Begin this section by saying that you drew up a list of sentences from the JC corpus which represent obligatory contexts for genitive ’s (in noun expressions like Daddy’s or the man next door’s) and that the list is included in your Appendix. Below, I have drawn up a list of (italicised) noun expressions which JC seems to use in genitive contexts (i.e. which he seems to use as possessors). 205 One possibility which you might want to consider is whether pincher is a novel noun formed by adding the nominalising (i.e. noun-forming) suffix –er to the verb stem pinch to form the noun pincher. It seems to be used in contexts where adults would use the word pincer. 206 If we excluded a pair lobster as indeterminate in status, this figure would rise from 89% to 100% suppliance. 81 (8) List of (italicized) noun expressions used by JC in genitive contexts (as possessors) 62 Me brother name Jack (= ‘My brother’s name is Jack’). 72 That can be Giovanni (= ‘Giovanni's’). 105 He shoveled someone else [?= ‘He shoveled someone else’s (snow)’]. 157. A girl hat (‘A girl’s hat’) 159 This is somebody else fishing (= ‘somebody else’s fishing game’) 161 Now it’s gonna be Matthew (= ‘Matthew’s turn’) cause, cause... 263. Where Giovanni one? (‘Where’s Giovanni’s one?’) 264 Where Giovanni sticker? (‘Where’s Giovanni’s sticker?’) 276 Me sister name Dawn (‘My sister’s name is Dawn’). You can then use the list in (8) to draw up a frequency table (which you include in the main body of your text) showing the relative frequency with which JC uses s-forms and bare forms in genitive contexts. Below, I’ve drawn up a partial table in order to give you an idea of what such a table might look like: (9) Raw frequency of noun-expressions used by JC in genitive contexts (as possessors) A: correct s-form B: bare form Giovanni = 3 me sister = 1 someone else = 2 Once you’ve drawn up your own complete version of the table in (9), you then need to calculate the frequency with which JC marks noun expressions with genitive ’s in obligatory contexts, using the procedure shown below: (10) % suppliance of genitive ’s on noun = expressions in obligatory contexts no. of tokens of genitive s-forms x 100 no. of obligatory contexts for genitive s-forms This amounts to adding up the number of correct s-forms you find in all the A-cells in (your complete version of) table (10), multiplying this by 100, and then dividing the resulting figure by the number of s-forms and bare forms you find in all the A- and B-cells together. If we do this calculation for the small fragment of data in table (10), we find that JC produces 0 (i.e. zero) s-forms in 6 genitive contexts, so his percent suppliance of genitive s-forms in obligatory contexts is 0% (i.e. 0/6 x 100). There is clearly little point in looking for possible perceptual effects (e.g. seeing if he performs better on genitive forms which involve the use of the vowel-containing |Iz| allomorph than on those which involve use of a purely consonantal allomorph like |z|), for the obvious reason that he performs equally badly (at a 0% suppliance level) on each. For the same reason, there is no point in trying to look for possible frequency effects. 2.4 Research results for present-tense s-forms of main verbs Begin this section by saying that you drew up a list of sentences from the JC corpus which represent obligatory contexts for third person singular present tense (3SgPres) s-forms of main verbs – and include this list in the Appendix to your project. In (11) below is a list of (italicised) main verbs which occur in potential 3SgPres contexts in the JC corpus (with glosses in parentheses giving the adult English counterpart)207: I have excluded utterance 348. Her’s use with a green thing from this (and other) lists, since its precise status is indeterminate. For example, ’s here may represent a contracted form of does (which would mean that he is using DO-support inappropriately). Alternatively, JC may have been trying to say She uses a green thing, and because he has not acquired the nominative pronoun she, uses the genitive form hers instead (though this doesn’t seem likely either, since he generally does not use genitive pronouns as subjects). 207 82 (11) List of (italicized) main verbs used by JC in third person singular present-tense contexts 44. When him crack tiny pieces up, and then put xxx (‘When he cracks tiny pieces up and then puts...’) 45. Then dump into a truck again (‘Then dumps them into a truck again’) 55. He like Danny talking like that (‘He likes Danny talking like that’) 64. He only have a coat (‘He only has a coat’) 65. Now he have them two (‘Now he has those two’) 67. He have a doctor (‘He has a doctor’) 99. But, me mom let (‘But my mum lets (me)’) 116. When he hold here (‘When he holds (it) here’) 117. Me daddy like mustard (‘My daddy likes mustard’) 121. And it stick to you (‘And it sticks to you’) 156. He have he hats on (‘?= He has his hats on’) 195. Her standing and her see herself (‘She’s standing and she sees herself’ – describing picture) 346. My dad make eggs, but mushy eggs (‘My dad makes eggs...’) 349. Her use with a green cutter thing (‘She uses a green cutter thing’) 352. He hafta (‘He has to’)208 353. Me mom hold in him hands (‘My mum holds it in her hands’) 356. He put in a box with lots different and jelly bean (‘He puts (it) in a box with lots of different things and jelly beans’) 357. Then he bring it (‘Then he brings it’) 360. Mom say, no, after lunch (‘Mom says ‘No, after lunch’) 370. Her need the camera to put in a locker (‘She needs the camera…’) 372. It look like a lobster (‘It looks like a lobster’) 376. He...him go first (‘He goes first’) You can use the list in (11) to draw up a table (which you include in the main body of your text) showing the relative frequency with which JC uses s-forms and bare forms of main verbs in 3SgPres contexts. Below, I’ve drawn up a partial table (with items listed in alphabetical order) in order to give you an idea of what such a table might look like: (12) Raw frequency of main verbs used by JC in third person singular present contexts Verb A: correct s-form B: incorrect bare form HOLD hold = 2 LIKE like = 2 LOOK look = 1 Once you’ve drawn up your own complete version of the table in (12), you then need to calculate the frequency with which JC marks main verbs with {s} in third-person-singular present-tense contexts, using the procedure shown below: (13) % suppliance of 3SgPres {s} on = main verbs in obligatory contexts no. of tokens of 3SgPres main-verb s-forms x 100 no. of obligatory contexts for 3SgPres main-verb s-forms This amounts to adding up the number of correct s-forms you find in all the A-cells in (your complete version of) table (12), multiplying this by 100, and then dividing the resulting figure by the number of s-forms and bare forms you find in all the A- and B-cells together. If we do this calculation for the small fragment of data in table (12), we find that JC produces zero s-forms of main verbs in five 3SgPres contexts, so his percent suppliance of {s} on main verbs in 3SgPres contexts is 0% (i.e. 0/5 x 100). There is clearly little point in looking for possible perceptual effects (e.g. seeing if he performs better on 3SgPres forms which involve the use of the vowel-containing |Iz| allomorph of {s} than on those which involve use of a purely consonantal allomorph like |s| or |z|), for the obvious reason that he performs equally badly (at a 0% suppliance level) on each. For analogous reasons, there is no point in trying to look 208 Hafta is a contracted form of have to, widely used in spoken American English. 83 for possible frequency effects (e.g. seeing whether he performs better on high- than low-frequency 3SgPres forms), since he scores equally badly (with a 0% suppliance rate) on all types of verb. 2.5 Research results for present-tense s-forms of auxiliaries Begin this section by saying that you drew up a list of sentences from the JC corpus which represent obligatory contexts for third person singular present tense auxiliary s-forms (both the full is/has/does forms and their contracted variant ’s) – and include this list in the Appendix to your project. In (15) below, I have drawn up such a list: in almost all cases, the relevant context is one for is209, the few contexts for does or has being shown in parentheses. (14) List of sentences produced by JC in contexts where adults use auxiliaries (i)s/(doe)s/(ha)s A: Sentences in which JC uses the full forms is/has/does 57. This girl is. 58. But he bus is over here. 75. Is a dog under a table210 160. This is a girl and this is a boy. 161. This is somebody else fishing. 162. This is you? (= This is yours?) 191. Dirt is falling all over him. 198. This black shadow is her and her. 208. Ooh, this is a scary one. 211. Is green. 224. I’n see that one, cause that one is very good. 248. This is gonna be hot dog. 249. This is gonna be coffee. 268. That because is shamrock today. 334. My another one is lost. 340. That mean is already cook. 386. This is a good one. B: Sentences in which JC uses the contracted form ’s 34. It’s a little bit night time. 56. He’s sick. 59. But, he’s not have no money (= does). 78. It’s a cat. 82. And that’s not for a baby. 126. And it’s gonna be all gone. 130. It’s hard to find this. 156. It’s a plane 157. He’s funny. 163. Now it’s gonna be Matthew211 cause, cause... 164. It’s gonna be my, cause I'm bigger than him. 173. It’s swinging. 175. He’s sad cause he can't go. 189. It’s a farm 190. He’s digging up dirt. 199. It’s her hair. 201. I think it’s a ghost. 202. It’s not, imagination. 207. It’s a... 209. It’s a owl. 220. Oh, that’s different Barney. 226. It’s a boat. 262. Who’s that? 271. That’s my speech teacher, a speech one. 276. It’s got eye (= has). 277. It’s a seagull. 284. Her say, ahh it’s moving. C: Sentences in which JC omits the auxiliary (from the underlined position) 4. That_me friend. 17. He_happy. 29. How long_the song gonna be on? 30. Why_it not being on? 39. But it_a truck you dump dirt, and snow… 51. It_very sharp. 54. But he_not there. 57. Her_not. 60. Her_pretending to being a doctor. 62. Me brother name_Jack. 76. He_under the table 77. Her_laying. 88. He_making a mess. 108. Who_that? 110. This one, he_cooking up a hot dog. 113. Ooh, that_gross. 147. Why_her need this? (= does) 151. Her_sad. 177. And he_sad cause he_crying. 180. He_crying, he_crying. 185. He can fly cause he_got these wings. (= has). 197. Her_standing. 206. He_flying. 218. It_just pretend. 219. He_not real. 223. He_got old one (= has). 230. _This a new game? 243. Daddy_got train (= has). 245. I don’t know what he_saying. 246. That_my brother. 258. That_not pepper. 265.Where_Giovanni one? 266. Where_Giovanni sticker? 268.That_because is shamrock today. 278. Me sister name_Dawn. 301.Her_eating a cookie. 316. How_he gonna eat me up? 317. He_grabbing a lollipop. 383. He_taking a lollipop. 384.He_gonna bite you. Using the data in table (14), you can then calculate how frequently JC supplies the auxiliaries (i)s/(doe)s/(ha)s in obligatory contexts using the following procedure: (15) 209 % suppliance of s-forms of auxiliaries = no. of tokens of s-forms of auxiliaries in obligatory 3gPres contexts no. of obligatory contexts for s-forms of auxiliaries The word is serves as a progressive auxiliary when followed by a verb in the progessive ing-form (as in He is working) and as a copular (i.e. linking) verb when followed by an adjectival, prepositional or nominal expression (as in He is happy/in Paris/a doctor). In both uses, is has the morphosyntax of an auxiliary, in the sense that e.g. it forms negatives and questions without the use of DO-support (cf. He isn’t happy/Is he happy?). 210 In utterances 75, 211, 268 and 340, is would appear to be a contracted form of it’s – though this is not clear. 211 Apparently meaning ‘It’s gonna be Matthew’s turn’ 84 The first thing you need to do is add up the number of times JC uses is/has/does/’s in the A- and B-rows in table (14), and multiply this figure by 100, to give you your top-line figure. You calculate your bottomline figure (i.e. the number of obligatory contexts for s-forms of auxiliaries) by adding up the total number of times JC uses and omits is/has/does/’s in A-, B- and C-rows columns in table (14). You then divide your top-line figure by your bottom-line figure to give you JC’s percent suppliance of s-forms of auxiliaries in obligatory contexts. If we were to do this calculation just for the (very small sample of) utterances numbered between 50 and 60 in the corpus, we’d find that JC uses s-forms 4 times (in sentences 56, 57, 58 and 59), and omits s-forms 4 times as well (in sentences 51, 54, 57, and 60). His suppliance rate for auxiliary s-forms in these 8 sentences is therefore 50%. Of course, you have to compute your own suppliance rate using all the data in table (14), not just the data from the 8 sentences I have chosen here for illustrative purposes. An interesting additional question to look at is whether JC fares better on uncontractible s-forms of auxiliaries than on their contractible counterparts (as the Perceptual Deficit model would lead us to expect). Auxiliary s-forms are uncontractible when (i) the last last word in a sentence (e.g. I wonder where he is), (ii) followed by a weak pronoun at the end of a sentence (e.g. What is it?) and (ii) occurring after a word ending in a sibilant (e.g. This is nice). If we exclude utterances 75, 211, 268 and 340 (because of the indeterminate status of is in the relevant sentences), the only utterances in the JC corpus which constitute obligatory contexts for uncontractible s-forms of auxiliaries are 57 (where is occurs at the end of a sentence), and 58/160/161/162/208/248/249/386 where the auxiliary occurs after a word ending in the sibilant |s|. If we do this, we can calculate JC’s suppliance rate for uncontractible s-forms of auxiliaries in terms of the following formula: (16) % suppliance of uncontractible s-forms = no. of tokens of s-forms in uncontactible contexts of auxiliaries in obligatory contexts no. of obligatory contexts for contractible s-forms For the reasons given above, utterances which could be taken to constitute obligatory contexts for contractible s-forms of auxiliaries are 57/58/160/161/162/208/248/249/386. You will then need to compare JC’s suppliance rate for uncontractible s-forms of auxiliaries with his suppliance rate for contractible forms. Obligatory contexts for such forms are all the utterances in list (15) except utterances which are indeterminate (75/211/268/340), which may involve truncation (230), or which are obligatory contexts for uncontractible s-forms (57/58/160/161/162/208/248/249/386). You can then compute his suppliance rate for contractible s-forms of auxiliaries using the following formula: (17) % suppliance of contractible s-forms = of auxiliaries in obligatory contexts no. of tokens of s-forms in contractible contexts no. of obligatory contexts for contractible s-forms The figures you arrive at in relation to (16) and (17) will enable you to copare how well JC fares on supplying contractible and uncotractible s-forms of auxiliaries in obligatory contexts. 2.6 Summary of research results In this section, briefly summarise your research results on how frequently JC supplies each of the different types of s-form covered in your study. 3. Analysis of research results (around 35% of your overall study) 3.1 Introduction Begin with an introduction saying that what you are aiming to do in this section/chapter is evaluate the extent to which the research findings that you obtained in the previous chapter are consistent (or inconsistent) with the research hypotheses which you outlined in chapter 1, and (more generally) with the particular models of SLI which you are aiming to test. Since the main aim of your research is to use your research results to evaluate a number of different theories of SLI, you are going to organise the material in this chapter into sections by theory – e.g. discussing the extent to which your research findings are 85 compatible with the Perceptual Deficit model in section 3.2, with the Rule Deficit model in section 3.3, with the Agreement Deficit model in section 3.4, and with the ATOM model in section 3.5. Below, I’ll assume the results reported in relation to partial sets of data in §2.2 (= 89% suppliance of {s} on regular nouns in plural contexts), §2.3 (= 0% suppliance of {s} on possessor in genitive contexts), 2.4 (= 0% suppliance of {s} on main verbs in 3SgPres contexts) and §2.5 (= 50% suppliance of s-forms of auxiliaries in 3SgPres contexts) – though your figures (based on complete sets of data) may be somewhat different from these, and your discussion must be based on your complete results, not my partial results. 3.2 Evaluation of the Perceptual Deficit model On the face of it, the Perceptual Deficit model would appear to predict that SLI children should have problems in acquiring all s-forms – and JC’s 0% suppliance of genitive {s} on noun expressions and 3SgPres {s} on main verbs would appear to be consistent with this claim. But the overall picture is not quite so straightforward, because JC also achieves 89% suppliance of plural {s} on nouns and 50% suppliance of s-forms of auxiliaries. It would appear that we need to assume that a perceptual deficit is only part of a more complex picture. For example, suppose that learning to use a morpheme in appropriate contexts involves a three-stage process – first perceiving the relevant form, then parsing it (i.e. working out what grammatical features it carries), then practising using it; and suppose that all three stages take considerably longer (e.g. twice as long) in SLI children as in normally developing children. We would then expect to find three types of effect. One is a perceptual effect (of the type that Leonard discusses), so that (all things being equal) we’d expect children to be better at vowel-containing forms than at purely consonantal forms. A second effect we’d expect to find is a frequency effect, in that children at an immature stage of development would be expected to perform better on forms which occur more frequently in their speech input than those which occur less frequently (because all three stages in learning how to use a morpheme require extensive exposure to the morpheme, and a child at a given stage of development will have had more exposure to high-frequency than low-frequency forms). The third effect we’d expect to find is a complexity effect, in that analysing the grammatical properties of a morpheme is going to take longer if the morpheme is a complex one encoding several features than if it is a simple one encoding a single feature (or if it encodes an uninterpretable feature, or an interpretable feature denoting a cognitively complex concept). You can in principle test for possible perceptual effects by looking at whether JC performs better on vowel-containing allomorphs of s-forms than on purely consonant allomorphs. However, given that he has a near-perfect score for plural s-forms (which would indeed have been perfect had we excluded the indeterminate phrase a pair lobster), and a zero score for genitive s-forms and 3SgPres s-forms of main verbs, there seems little point in doing so. But one place where you can look for possible perceptual effects is in JC’s production of auxiliary s-forms, where the Perceptual Deficit model would lead us to expect that he should perform much better on supplying uncontractible than contractible forms – and the results you obtained in §2.5 will help you determine whether this is so. But even if JC is much better at supplying uncontractible than contractible auxiliary s-forms, you might want to ask whether this necessarily represents a perceptual deficit, or whether (e.g.) it could be the result of phonological production problems caused by consonant clusters formed when ’s follows a word ending in one or more consonants, and/or precedes a word ending in one or more consonants. What about possible frequency effects? For example, could it be that one reason why JC performs well on plural {s} but badly on genitive {s} and on 3SgPresent {s} is that plural s-forms occur far more frequently than genitive s-forms or 3SgPresent s-forms? Unfortunately, although a frequency dictionary like Carroll (1971) will tell you the relative frequency (per million words) of individual plural noun-forms and 3SgPresent verb-forms in adult English212, it won’t give you the frequency of genitive s-forms, since these 212 The frequency figures (per million words) for relevant 3SgPres s-forms in adult English given by Carroll are as follows (with the frequency of the corresponding bare form in parentheses): is = ???? (be = 60852); has = 10369 (have = 22337); means = 1962 (mean = 1266); makes = 1311 (make = 8333); says = 1180 (say = 3916); goes = 930 (go = 5388); looks = 756 (look = 4933); needs = 616 (need = 2281); uses = 603 (use = 7009); sticks = 242 (stick = 501); likes = 229 (like = 9696); holds = 228 (hold = 1192); sees = 180 (see = 8515); brings = 169 (bring = 1016); 86 often attach to phrases (and there are an infinite set of possible phrases, so a frequency dictionary cannot list them). To help you get round this problem (and because a frequency dictionary like Carroll’s isn’t based on parental speech input to children), I calculated the frequency with which various s-forms occurred in parental speech in 20 files from the Abe corpus on the CHILDES data-base (each file representing about 10 minutes of conversation between a two-year-old normally developing boy called Abe and his mother and/or father). During these files, Abe’s parents produced 119 tokens of regular noun plural {s}, 91 of regular 3SgPres {s}, and 5 of genitive {s} on noun expressions; they also produced 343 tokens of the irregular 3SgPres auxiliary (i)s, 22 of the auxiliary (doe)s and 7 of the auxiliary (ha)s. Of course, it has to be said that this is only a small sample of (3 hours or so) of the speech production of the parents of one child – but at least they give you some kind of indication of likely relative frequencies. In order to test for a possible complexity effect, you need to ask yourself how many grammatical features each of the various s-forms produced by JC encodes, and whether this accounts for why he performs better on some than others. But you need to bear in mind that you can only test for a complexity effect by comparing simple and complex forms which have roughly the same frequency of occurrence, since otherwise, there may be a frequency effect which skews the complexity effect. So, for example, if you wanted to compare s-forms on nouns and main verbs, you’d need to compare sets of forms with roughly the same frequency in adult English. Since your project is designed to test your intelligence and initiative and not mine, I leave you to think out how to do this! If you find evidence of the three effects suggested above, you could conclude this section by discussing the extent to which the interaction of these three effects might account for your overall research findings. How do you do that? By using your initiative and intelligence and demonstrating that you can think a problem through (and find possible solutions) for yourself - after all, problem-solving is one of the key skills which you’re supposed to demonstrate evidence of in your academic work! 3.3 Evaluation of the Rule Deficit model The Rule Deficit model claims that SLI children are unable to acquire regular morphological rules like the present-tense s-rule in (1), the plural s-rule in (2) and the genitive s-rule in (3): one prediction which this makes is that children with SLI will not produce novel or over-regularised s-forms. The model maintains that the only way they can acquire inflected forms (including s-forms) is by memorisation. Since memorisation (and the ability to retrieve a memorised form) improves with increased exposure, we’d expect to find a correlation between the suppliance rate for individual inflected word-forms and the frequency of the relevant form (e.g. that an SLI child achieves 80% suppliance of a high-frequency form, 50% suppliance of a medium-frequency form, and 20% suppliance of a low-frequency form). So, the first thing you need to look at is the extent to which you find any evidence of frequency effects. Since how to do this is discussed in the previous section, I won’t repeat the relevant material here. But bear in mind the possibility of a secondary frequency effect mentioned by Gopnik and Crago – namely that SLI children tend to perform poorly on inflected forms which are less frequent than the corresponding bare form: for example, could it be that one reason why JC uses the bare form like in contexts where adults use the inflected (third person singular present tense) s-form likes is that like is 33 times more frequent than likes? bear in mind that any frequency effect may in turn be skewed by a complexity effect (e.g. if two inflected forms have the same frequency but differ in complexity, a child would be expected to be better at the simpler one). Suppose that you don’t find any clear evidence of any frequency effect. What then? You might feel tempted to conclude that the Rule Deficit theory is thereby falsified. But before throwing out a theory, you need to ask whether it can be modified in some way which will salvage it. Suppose, for example, that rather than following Gopnik and Crago (1991) in hypothesising that SLI children (because of a genetic deficit) are unable to acquire regular morphological rules, we instead hypothesise that they show a delay puts = 156 (put = 3942); cracks = 81 (crack = 144); lets = 70 (let = 2176); dumps = 8 (dump = 33). The frequency figures Carroll gives for relevant plural s-forms of nouns (and of their bare counterparts) are: 87 in acquiring morphological rules (e.g. perhaps they require twice as much exposure as normally developing children, and hence take twice as long to acquire regular rules). If SLI children are indeed considerably slower than normally developing children in acquiring regular morphological rules, we might expect that a child (like JC) who is at an immature stage of development will show evidence of having acquired some morphological rules, but not others. For example, suppose that JC has acquired the defective (i.e. incomplete) set of regular morphological rules shown below: (18) A regular verb carries the suffix {d} if past213, {ing} if progressive or gerund, {ø} otherwise (19) A regular noun carries the suffix {s} if plural, {ø} otherwise I leave you to think through whether this would account for (some or all of) your research results. 3.4 Evaluation of the Agreement Deficit model The core assumption of the Agreement Deficit model is that SLI children have problems in acquiring uninterpretable agreement features (but not interpretable features or other uniterpretable features). My preliminary findings (based on a very small subsample of the JC corpus) seem to lend some support to this claim, in that JC achieves a very high (89%) suppliance rate for plural -s on nouns (which marks an interpretable number feature), but a 0% suppliance rate for regular 3SgPres -s (which marks uninterpretable agreement features). However, my preliminary finding that JC has a 0% suppliance rate for genitive ’s seems incompatible with the prediction made by Clahsen, Bartke and Göllner (1997) that SLI children are very good at case-marking (their paper reporting 100% correct suppliance of case marking by the English children in their study). However, work in other studies (e.g. Loeb and Leonard 1990, and Bishop 1994) has shown that younger SLI children do indeed have problems with casemarking. We might therefore want to follow Tsimpli and Stavrakaki (1999) in concluding that SLI children have problems with all uninterpretable features: let’s call this the Uninterpretable Feature Deficit Hypothesis/UFDH. This would then account for why JC scores 89% correct on plural -s (which marks an interpretable number feature), but 0% correct on 3Sg -s (which marks uninterpretable agreement features) 0% correct on genitive ’s (which marks an uninterpretable case feature). Note, however, that UFDH would also predict that SLI children like JC should have problems in acquiring irregular genitive pronouns like my/our/your/their etc, and should use default (accusative) forms in genitive contexts. You can test this by calculating JV’s suppliance rate for genitive pronouns in obligatory contexts. Because your main concern is with s-forms and not with pronouns, you can limit yourself to looking at how he case-marks the most frequent type of pronominal possessor he uses – namely first person singular possessors. Below I have listed all the first person singular possessors used by JC in the corpus: (20) List of first person singular personal pronouns used in genitive contexts by JC A: Genitive my possessors B: Default accusative me possessors 101. Somebody else asked my mom to play outside 4. That me friend with them 62. Me brother name Jack 162. It’s gonna be my, cause I’m bigger than him. 71. All of these can be me 166. I got on my shirt and have trouble doing my back 99. But, me mom let 203. I can make see my shadow 242. Me daddy 244. That my brother 267. Me teacher make cake 269. That’s my speech teacher… 276. Me sister name Dawn 326. Then a bee eat a little bit my food 277. Her give me dad a lobster, a two lobster 335. My another one is lost 278. Me mom put in here, cook them 346. My dad make eggs, but mushy eggs 309. Me grandma did long time ago from a snake 359. Then, I grab my one 337. Me mommy show me to make Easter eggs 365. I got my hair from barber 347. Me mom don’t use paint brush 366. But them cut my hair real tiny 353. Me mom hold in him hands 213 There are not enough relevant examples in the corpus to be sure whether JC makes productive use of regular perfect and passive participle d-forms, so I have not included these here. 88 From this list, using prodecures which by now should be yawningly familiar, you can calculate JC’s percent suppliance rate for first person singular genitive pronouns in obligatory contexts (multiplying the number of italicised forms in column A by 100, and dividing this sum by the total number of italicised forms in columns A and B together). If JC’s suppliance rate for my is much higher than for ’s, why do you think this might be – e.g. could frequency be a factor? 3.5 Evaluation of the ATOM model The ATOM model claims that SLI children have particular problems in marking tense and agreement, and sporadically omit either or both of these features on verbs in finite contexts (i.e. in contexts where adults would use a verb which is marked for both tense and agreement). ATOM also assumes that case is tied up with agreement, and that SLI children use correctly case-marked forms when they mark agreement, and default (accusative) forms when they fail to mark agreement. If (in line with the discussion in §1.6) we assume that plural number on nouns is not an agreement feature, we’d expect JC to show a very high suppliance rate for marking plural number on nouns in obligatory contexts (the relevant rate being determined by the procedure in (7) above). If (again in line with the discussion in §1.6) we take genitive case to be a reflex of possessor-agreement, then one possible ATOM account of why JC never uses genitive {s} would be that he has not acquired possessor-agreement, with the result that possessors are always assigned default accusative case (and so surface as bare s-less nominals like Giovanni in Giovanni sticker). But an immediate problem with this analysis is that ATOM claims that SLI children only sometimes fail to mark agreement in obligatory contexts – a claim which would seem to predict that JC should alternate between structures containing an agreementless accusative possessor (as in Daddy car where Daddy would be a bare accusative possessor) and structures containing an agreeing possessor carrying the genitive {s} suffix (as in Daddy’s car, where Daddy’s would be an s-marked genitive possessor). Still, maybe JC has acquired subject agreement (between subject and verb) at this stage, but not possessor-agreement – perhaps because the former is far more frequent than the latter (in that almost every sentence contains a subject agreeing with a verb, but by no means every sentence contains a possessor). You can test whether JC does or doesn’t sporadically mark possessor agreement by calcxulating his suppliance rate for first person singular genitive pronouns in the contexts lised in table (20), uswing the procedure outlined in the previous section. If he sporadically marks possessor agreement in genitive contexts, we’d expect him to alternate between (agreeing) genitive possessors like my and (non-agreeing) default accusative possessors like me. Is this what we find? Suppose (for the sake of argument) that he assigns genitive case to around half the first person pronouns pronoun possessors he uses. What we’d then expect would be that around half of his nominal possessors should carry the genitive {s} suffix, and around half should be bare (s-less) expressions. But this is not the picture we find. Why do you think that might be? Let’s now consider the predictions ATOM makes about how SLI children treat main verbs in 3SgPres contexts, and whether these are borne out. For the reasons set out in §1.6, ATOM predicts that in contexts where adults would produce a sentence like He plays with me, an SLI child who has acquired the third person singular present tense morpheme {s} will alternate between producing nominative-subject sentences like He plays with me and He play with me, and accusative-subject sentences like Him play with me (though not *Him plays with me). But what would ATOM predict about a child like JC who seems not to have acquired the 3SgPres morpheme {s}? I leave you to answer this question for yourself. In order to determine the extent to which the relevant predictions about which types of subject will (and won’t) occur with which types of verb in 3SgPres contexts, you need to use the data in the list in (11) above to draw up a separate list of sentences produced by JC with nominative and accusative personal-pronoun subjects in contexts where adults would use a 3SgPres main verb (excluding it subjects because these show no nominative-accusative contrast). I’ve drawn up a partial list for illustrative purposes below (the relevant subjects being italicised and their associated verbs bold-printed): 89 (21) List of nominative and accusative subjects that JC uses with main verbs in 3SgPres contexts A: Nominative subjects B: Default accusative subjects 55. He like Danny talking like that 44. When him crack tiny pieces up… 64. He only have a coat 195. Her standing and her see herself When you’ve drawn up a complete version of the list in (25), you need to ask yourself to what extent the set of structures JC produces is consistent with the predictions made by ATOM. The last set of structures to look at are those containing auxiliary s-forms. For the reasons set out in §1.6, ATOM predicts that in contexts where adults would say He’s sleeping, SLI children would say He’s sleeping, He sleeping, and Him sleeping – but not *Him’s sleeping. In order to determine the extent to which these predictions are borne out, you need to use the data in the list in (14) above to compile a separate list of sentences produced by JC with nominative and accusative subjects in contexts where adults would use a 3SgPres main verb (excluding it subjects because these show no nominative-accusative contrast). Again, I’ve drawn up a partial list for illustrative purposes below: (22) List of nominative and accusative subjects that JC uses with auxiliaries in 3SgPres contexts A: Nominative subjects B: Default accusative subjects 56. He’s sick 60. Her_pretending to being a doctor 17. He_happy 147. Why_her need this? 59. But, he’s not have no money. 223. He_got old one When you’ve drawn up a complete version of the list in (22), you need to ask yourself to what extent the set of structures JC produces is consistent with the predictions made by ATOM. Are there any discrepancies, and (if so) how do you think they can be accounted for, and to what extent do they undermine ATOM (if at all)? Chapter 4. Summary and Conclusions (about 15% of your overall study) 4.1 Summary of research hypotheses Begin this chapter with a section in which you provide a brief summary of the models of SLI and research hypotheses which you outlined in chapter 1. 4.2 Summary of research findings In this section, briefly summarise the main research findings you obtained in chapter 2 4.3 Summary of evaluations In this section, provide a brief summary of your evaluation (in chapter 3) of the relative strengths and weaknesses of each of the theories of SLI you are testing, viewed from the perspective of how well they account for your own research findings. 4.4 Overall conclusions In this (the most important) section of your chapter, you need to give your considered final verdict on which of the models you have looked at best accounts for your own research findings. If a particular model doesn’t account for (some of) your findings, can it be modified in some way which would make it compatible with your findings? If not, and if there is no one model of SLI which accounts for all your research findings, does this take you towards a composite model which sees SLI as involving multiple impairments, rather than a single type of impairment? Such a composite model might say something along the following lines in relation to how an SLI child acquires a plural noun like cats (cf. the remarks I made earlier in section 3.2). The first stage (I) is phonological processing, and perceiving that the form comprises the segments |kats|. The second stage (II) is grammatical processing – i.e. determining what grammatical features the word cats carries, and what its 90 internal structure is. Children who are at stage I in respect of the acquisition of a given morpheme may go through a short stage like that described in Gopnik’s (1990) Feature Blindness model when they have learned cat and cats as separate word-forms, but are not aware of the grammatical distinction between the two forms, and so use both forms in singular and plural contexts alike (hence alternating between a cat and a cats, and between two cat and two cats). The first phase of grammatical processing (stage IIA) is feature decomposition – i.e. decomposing words into the set of features they carry (e.g. realising that cats encodes a plural number feature): a child who is at this phase will be learning plural forms (regular and irregular alike) by memorisation. The second phase of grammatical processing (IIB) is morphemic segmentation – e.g. abstracting a common plural formation pattern from contrasts like cat/cats, dog/dogs, car/cars and segmenting each regular plural noun into a stem and a plural affix {s}, and working out what different allomorphs plural {s} has, and what conditions govern the use of each allomorph. The third stage is practising the use of the relevant morpheme – in this case, plural {s}. Let’s suppose that all three stages of this process of learning how to use a morpheme take considerably longer in SLI children as in normally developing children – maybe because they process all aspects of language (say) twice as slowly as normally developing children. Such a composite model would enable us to incorporate elements of a number of different theories of SLI. For example, a perceptual deficit of the kind postulated by Leonard would mean that phonological processing takes much longer than in normal children. And If SLI children are also much slower to analyse words into their component features than normally developing children, then we could follow Gopnik (1990) in saying that they have a feature deficit (though not in the sense that they are ‘blind’ to grammatical features and hence unable ever to acquire such features, but rather in the sense that they are slow to acquire grammatical features). We might also expect to find that certain types of feature are more difficult to acquire than others – e.g. perhaps uninterpretable features are intrinsically more difficult to acquire than interpretable ones (as suggested by Clahsen, Bartke and Göllner 1997), and perhaps some types of interpretable feature are particularly difficult to acquire (e.g. tense – as in the ATOM model) because of their conceptual complexity. All other things being equal, we might also expect that a morpheme which encodes multiple grammatical features will be more difficult to acquire than one encoding a single feature. And if SLI children are slower at grammatical processing than normally developing children, we’d expect them to be slower at segmenting words into stems and affixes, and at acquiring the morphophonological rules which govern the use of affixes, so that at a particular phase (IIA) in their development, they may have a rule deficit in the sense that they have not yet acquired one or more regular morphological rules and so learn relevant inflected forms by memorisation – though Gopnik and Crago’s 1991 claim that SLI children are unable ever to form any regular rules may simply be too strong, and we also need to bear in mind the possibility that at a given point of development, an SLI child may be at a later stage/phase in the acquisition of (say) plural {s} than genitive {s}. Moreover, it would seem reasonable to suppose that morphemes with multiple allomorphs (whose distribution is determined by complex phonological factors) will take longer to acquire than those with a singe allomorph, for the obvious reason that the child has to work out the morphophonological rules governing the use of the relevant allomorphs. And once children have acquired a morpheme (and learned the rules which govern its use), they need time to practice using it – perhaps considerably more time than normally developing children. The kind of composite model of SLI which I have outlined here would also lead us to expect to find frequency effects, since the first two stages of the process – phonological and grammatical processing – require extensive exposure (to thousands of tokens of a given morpheme), and the threshold number of exposures required in order to achieve a given level of performance will be reached much earlier for highfrequency morphemes than for low-frequency ones. Of course, it’s one thing to sketch out a composite model like that which I have outlined above which sees SLI as affecting a number of different components of the grammar, and quite another to show how such a model could account for your specific research results. The question which you have to answer in your conclusion is: how (if at all) could such a composite model of SLI account for your specific results in relation to how well JC fared on each of the different s-forms you looked at. Be particularly circumspect in what you say in this part of your project: the conclusion is usually the weakest point in student work, and (if so) will devalue your overall project. 91 5. Appendices After your four main chapters, include as an Appendix any lists of sentences which provide the raw data from which you computed the figures for various tables included in the main body of your project, and any tables from which you have computed suppliance rates (and any other figures you use). 6. List of references After any Appendices, include a list of works (arranged alphabetically by author and date) which you have cited in your project, using the standard author-date system described in the departmental handbook. 92 10. Study III: Acquisition of inflected main-verb forms in English In this chapter, I look at how to undertake an empirical study of The acquisition of inflected main-verb forms in English by a 4-year-old child with SLI. Your study might be organised as follows. 1. Background (about 25% of your overall study) 1.1 Introduction Give brief details (in a paragraph or two) of the kind of developmental disorder which SLI involves (summarised on p.4 of this book: see Bishop (1997), Leonard (1998), and the collection of papers in Bishop and Leonard (2000) and Levy and Schaeffer (2003) for more detailed discussion of diagnostic criteria for SLI), pointing out that various aspects of grammar are reported to be impaired in SLI children, including the ability to produce inflected forms. Then go on to say that there are a wide range of different models of SLI which seek to account for the nature of the grammatical impairment in SLI children, and for the purposes of the present study you are going to examine a subset of these (e.g. the Perceptual Deficit, Rule Deficit, Agreement Deficit and ATOM models). Your aim is to do a small-scale empirical study designed to evaluate each of the models, by looking at the production of three types of inflected forms of main verbs in obligatory contexts by a four-year-old American boy with SLI, known as JC. Provide brief details of JC’s background (which you can find at the beginning of chapter 13). The three types of inflected forms of main verbs which you are going to look at are (i) past tense forms, (ii) third person singular present tense forms, and (iii) progressive participle forms. You’re going to exclude other inflected forms of main verbs (in particular, perfect participles, passive participles and gerunds) from your study because there are insufficient obligatory contexts for them in the JC corpus for you to draw any firm conclusions about his production of them. You’ll begin by outlining the morphophonology of the three main-verb forms that you are focusing on. 1.2 Outline of the morphophonology of inflected forms of main verbs in English In this section, you need to provide a brief account of the morphophonology of the three types of inflected main-verb forms which you are studying. The dual mechanism model of the acquisition of morphology (outlined e.g. in Pinker and Prince 1988 and Pinker 1991) maintains that irregular forms are memorised forms which are stored/listed in the mental lexicon, whereas regular forms are computed or derived via application of morphological rules like those sketched informally in (1) below (with morphemes enclosed in curly brackets, by convention): (1) A regular verb carries the suffix {s} if third person singular present {d} if past, perfect or passive {ing} if progressive or gerund {ø} otherwise The morphemes {s} and {d} have a variety of different allomorphs (i.e. variant forms), and the use of these is determined by by morphophonological spellout rules like those in (2) and (3) below: (2) {s} is spelled out as: |Iz| when attached to a form ending in a sibilant consonant (e.g. passes, buzzes, catches, cages, pushes, camouflages) |z| when attached to a form ending in another voiced segment214 (e.g. calls, robs, bags, grows, pays) |s| when attached to a form ending in another voiceless segment215 (e.g. cuts, locks, breaks, rocks) |ø| when attached to a form already ending in {s} (e.g. the boys’ school, where genitive {s} has a null spellout by virtue of being attached to a noun boys carrying plural {s}) Since all vowels are voiced, this means ‘when attached to a stem ending in a vowel, or a voiced non-sibilant consonant’. 215 In other words ‘when attached to a voiceless consonant which is not a sibilant’. 214 93 (3) {d} is spelled out as: |Id| when attached to a stem ending in an alveolar stop – i.e. |t| or |d| (e.g. padded, batted) |d| when attached to a stem ending in another voiced segment216 (e.g. moved, sneezed, paid) |t| when attached to a stem ending in another voiceless segment217 (e.g. passed, packed, laughed) By contrast, the morpheme {ing} is uniformly spelled out as |Iŋ| in standard varieties of English (though as |In| in non-standard varieties). How the system works for regular main verbs can be illustrated in the following terms. The lexical entry (i.e. entry in the dictionary) for the regular verb HELP will contain the stem form help-. The third person singular present-tense form of HELP will be derived by adding the suffix {s} to the stem in accordance with the first line of rule (1) so deriving help-s: the {s} suffix will be spelled out as |s| in accordance with the third clause of rule (2), so that the word is pronounced |helps|. The past tense form of HELP will be generated by adding the the suffix {d} to the stem form in accordance with the second line of rule (1), so deriving helped; the {d} suffix will be spelled out as |t| in accordance with the third line of rule (3), so that the word is pronounced |helpt|. The progressive participle form of HELP is derived by adding the suffix {ing} to the stem in accordance with the third line of rule (1), so forming helping; the {ing} suffix is spelled out as |Iŋ| in standard varieties, so that the resulting progressive participle is pronounced |help Iŋ| By contrast, the lexical entry for the irregular main verb CATCH will specify that it has the irregular past/perfect/passive form caught, and the fact that the verb is listed in the lexicon as having this irregular form will block application of the regular d-rule in (1) to irregular verbs like CATCH. Since no verbs have irregular progressive participle forms in English, its progressive participle will be formed by adding {ing} to the stem form catch-, so forming catching. Likewise, since catch is regular in respect of its present tense formation, its 3SgPres form will be derived by adding {s} to the stem form catch-, deriving catches. While the 3SgPres form of the vast majority of main verbs is entirely regular in English (as with e.g. helps, works, sleeps, cries etc.), there are three 3SgPres main-verb forms which are irregular – namely says, has and does (the last two of which function as main verbs in sentences such as He has a flat in town or He does a lot of work for charity)218. For details of ways in which these forms are irregular, see section 1.2 of chapter 9. Empirical research is about testing research hypotheses, so in sections 1.3-1.6, you should provide a short summary of the overall claims made by each of the models of SLI which you have decided to evaluate, and then go on to say what specific prediction each makes about how well SLI children would be expected to perform on each of the three types of inflected forms of main verbs which you are looking at. Of course, if you are looking at only 3 of the 4 models of SLI dealt with here, you will omit the section on the model that you are not dealing with. 1.3 Outline of the Perceptual Deficit model of SLI In this section you should provide an outline of the Perceptual Deficit model, noting that it claims that consonantal inflections pose more perceptual problems for SLI children than vocalic inflections, and saying what this predicts about how SLI children will perform on producing the three types of inflection you are concerned with here. In relation to progressive {ing}, the Perceptual Deficit model predicts that this should be relatively unproblematic for SLI children, in that the morpheme {ing} contains a vowel. For the predictions made about past tense forms of main verbs, see section 1.3 of chapter 8. For the predictions about 3SgPres forms of main verbs, see section 1.4 of chapter 9. Since all vowels are voiced, this means ‘when attached to a stem ending in a vowel, or a voiced consonant other than |d|’. 217 In other words ‘when attached to a stem ending in a voiceless consonant other than |t|’. 218 Has and does also have alternative uses as auxiliaries, but if you are focussing on main verbs, you should not include these auxiliary uses in your project. Likewise the irregular 3SgPres form is should be excluded from your project because in all uses it functions as an auxiliary (e.g. in that it has the contracted negative form isn’t and undergoes inversion in questions like Is it raining again?). 216 94 1.4 Outline of the Rule Deficit model of SLI In this section you should provide an outline of the Rule Deficit model, which claims that SLI children have a genetic rule deficit that makes it impossible for them to acquire any regular morphological rules. They are therefore predicted to be unable to acquire the regular present tense s-rule, the past-tense d-rule, or the progressive ing-rule outlined in (1) above, and are likewise predicted to be unable to create novel or over-regularised forms219. Because of this genetic rule deficit, the only learning mechanism which SLI children have is memorisation, with the consequence that they have to memorise all verb-forms, regular and irregular alike. Since memorisation of a given form requires extensive exposure to the relevant form, we therefore expect to find a frequency effect (viz. that the more often a child hears a given present, past or progressive main-verb form, the more often the child is likely to produce it correctly). More specifically, if Gopnik and Crago are right in claiming that SLI children have a rule deficit, we should expect to find a frequency effect with both regular and irregular main verbs alike, with childen being better at high-frequency inflected forms than at low-frequency inflected forms. But if Gopnik and Crago are wrong and SLI children (like normally developing children) learn regular forms by rule, we should expect to find that they perform at the same level on all regular inflected forms of the same type (e.g. equally well or badly on all regular past-tense d-forms of main verbs). 1.5 Outline of the Agreement Deficit model of SLI In this section you should provide an outline of the Agreement Deficit model, which claims that SLI children have particular problems with acquiring uninterpretable agreement features, but not with acquiring interpretable features. In relation to past tense forms, the model predicts that these pose few problems for SLI children, since tense is an interpretable feature (and past tense forms do not overtly inflect for uninterpretable person/number agreement features). Likewise, since progressive {ing} encodes an interpretable progressive-aspect feature (indicating that the event described by the relevant verb is in progress), we should expect SLI children to have few problems in acquiring it. However, the picture is different in relation to 3SgPres forms, in that the s-affix they carry encodes not only an interpretable present-tense feature, but also uninterpretable (third-person, singular-number) agreement features, and we would therefore expect that their uninterpretable agreement features will mean that s-forms are difficult for SLI children to acquire. 1.6 Outline of the Agreement-and-Tense-Omission (ATOM) model of SLI In this section, you should provide an outline of the Agreement-and-Tense-Omission/ATOM model, which claims that SLI children go through an Extended Optional Infinitives/EOI stage during which they sometimes fail to mark either tense and/or agreement in finite contexts (i.e. in contexts where adults use an auxiliary or main verb marked for tense and agreement). The presence or absence of agreement on the verb will affect the case assigned to the subject (in that a nominative subject is used when agreement is marked and a default accusative subject when it is not). On what ATOM predicts will happen with main verbs in past tense contexts, see section 1.7 of chapter 8. On ATOM’s predictions about what will happen with main verbs in 3SgPres contexts, see section 1.6 of chapter 9. In relation to progressive {ing}, ATOM seemingly predicts that SLI children should perform relatively well on progressive ing-forms, since {ing} marks progressive aspect and not tense or agreement (and ATOM claims that it is tense and agreement features which pose particular problems for children with SLI). 1.7 Summary of research hypotheses being tested In this section, you should briefly summarise the set of research hypotheses you have set out to test in your project in relation to each of the models of SLI which you have chosen to evaluate. 219 However, it should be noted that Ullman and Gopnik (1994) maintain that in spite of their inability to form implicit (i.e. subconsciously internalised) rules, SLI children who have undergone extensive therapy may learn an explicit (i.e. consciously memorised) rule taught to them by therapists or teachers to the effect that (e.g.) ‘A regular verb used in a past tense context ends in -d’. This means that the production of over-regularised forms does not necessarily ‘prove’ that a child has developed a subconsciously internalised past tense formation rule. 95 2. Research results (about 20% of the overall study) 2.1 Introduction Begin by noting that in this chapter/section you are setting out to test the predictions made in your chosen theories of SLI by examining the types of structure produced by JC in contexts where adults would use a progressive ing-form, a past-tense form or a third-person-singular present-tense form of a main verb. You will look at the range of verb-forms he uses in contexts where adults would use a progressive ing-form of a main verb in §2.2, a past-tense main-verb form in §2.3, and a present-tense main-verb s-form §2.4. You will then summarise your main research findings in §2.5. 2.2 Forms used by JC in contexts where adults use a progressive main verb The first thing to do is to draw up a list of (like that in (5) below) of (italicised) verb-forms used by JC in contexts where an adult would use a progressive-participle ing-form of a main verb: (4) List of (italicised) verb-forms used by JC in contexts where adults require progressive {ing} 18. Now, going home cause it melted 28. Me talking (a)bout... 29. How long the song gonna220 be on? 221 30. Why it not being on? 60. Her pretending to being a doctor 77. Her laying 86. I’m cooking something for dinner 88. He making a mess 89. Me making nice and neat 96. Me watching about it 108. This one, he cooking up a hot dog 124. And it’s gonna be all gone 141. What beach you going? 150. Me making a car 161. Now it’s gonna be Matthew cause, cause... 162. It’s gonna be my, cause I’m bigger than him 171. It’s swinging 175. And he sad cause he crying 178. He crying, he crying 186. I’m gonna have to pick it up first 188. He’s digging up dirt 189. Dirt is falling all over him 195. Her standing and her see herself 204. He flying 246. This is gonna be hot dog 247. This is gonna be coffee 284. Her say, ahh it’s moving 302. Her eating a cookie 317. How he gonna eat me up? 318. He grabbing a lollipop 320. What’s I talking about? 322. Then, I eating food 325. But a bee eating it 333. We making books 377. He taking a lollipop 378. He gonna bite you You can then use this list to calculate JC’s suppliance rate for progressive {ing} in accordance with the following procedure: (5) Percent suppliance rate for = number of tokens of progressive ing-forms produced by JC progressive {ing} number of obligatory contexts for progressive {ing}222 If (for illustrative purposes) we were to do this calculation for the first 10 utterances in the above list, JC’s suppliance rate for progressive {ing} would be 100% (based on the fact that he uses 10 progressive ing-forms in 10 obligatory contexts). 2.3 Forms used by JC in contexts where adults use a past-tense main verb In this section, you should follow the procedures set out in sections 2.1, 2.2 and the first part of 2.4 (relating to how frequently he marks past tense) of chapter 8. 2.4 Forms used by JC in contexts where adults use a third person singular present-tense main verb In this section, you should follow the procedures set out in section 2.4 of chapter 9. 220 Note that gonna is a contracted form of going to (extremely common in colloquial American English), and so should be treated as (containing) an ing-form. 221 This presumably corresponds to the adult form Why’s it not being on? What’s odd about this is that adults don’t generally use the verb BE in a progressive ing-forms unless it denotes an activity (e.g. He’s being naughty again). You could of course decide to exclude this utterance from your table, if you think it is of indeterminate status. 222 I.e. the number of times an adult would have used a progressive ing-form in the (adult counterpart of the) relevant sentences. 96 2.5 Summary of your research results In this section, you should present a summary of your main research results. For example, on the basis of the small subset of data for which I did the relevant calculations in section 2.2 of this chapter, section 2.2 of chapter 8 and section 2.4 of chapter 9, I arrived at the conclusion that JC’s rate of supplying correct forms of main verbs in obligatory contexts is 100% for progressive ing-forms, 0% for third person singular present tense s-forms, 45% for regular past tense forms, and 27% for irregular past tense forms. (Of course, since my calculations were done for illustrative purposes on only a small subset of the relevant data, your results may be quite different from mine.) 3. Analysis of research results (around 40% of your overall study) 3.1 Introduction Begin with an introduction saying that what you are aiming to do in this section/chapter is evaluate the extent to which the research findings that you reported in section 2.5 are consistent (or inconsistent) with the research hypotheses which you outlined in chapter 1, and (more generally) with the particular models of SLI which you are aiming to test. Since the main aim of your research is to use your research results to evaluate a number of different theories of SLI, you’re going to organise the material in this chapter into sections is by theory, discussing the extent to which your research findings are compatible with the Perceptual Deficit model in section 3.2, with the Rule Deficit model in section 3.3, with the Agreement Deficit model in section 3.4, and with the ATOM model in section 3.5. 3.2 Evaluation of the Perceptual Deficit model As noted in §1.3 in this chapter, the Perceptual Deficit model predicts that progressive {ing} should pose comparatively few perceptual problems for an SLI child like JC, since it contains a vowel (albeit a short, unstressed |I| vowel) – and my partial score223 of 100% correct use of progessive {ing} in obligatory contexts by JC would be consistent with this prediction. By contrast, present-tense {s} would be expected to pose far greater perceptual problems, for two reasons. Firstly, its two most frequent allomorphs |s| and |z| are purely consonantal (the vowel-containing allomorph |Iz| being restricted to use with stems ending in a sibilant consonant). And secondly, the fact that {s} has three distinct allomorphs (each subject to complex phonological restrictions on its use) arguably increases the perceptual problems it poses – at least, if we assume that (all other things being equal) a morpheme which has multiple allomorphs poses greater perceptual problems than one which has a single allomorph. I leave you the task of thinking through for yourself whether JC’s past tense marking is consistent with the Perceptual Deficit model: for some relevant discussion, see section 3.2 of chapter 8. You might like to bear in mind the remarks made in section 3.2 of chapter 9 – and in particular, the following paragraph: Suppose that learning to use a morpheme in appropriate contexts involves a three-stage process – first perceiving the relevant form, then parsing it (= working out the grammatical features it carries), then practising using it: and suppose that all three stages take considerably longer (e.g. twice as long) in SLI children as in normally developing children. We would then expect to find three types of effect. One is a perceptual effect (of the type that Leonard discusses), so that (all things being equal) we’d expect children to be better at vowel-containing forms than at purely consonantal forms. A second effect we’d expect to find is a frequency effect, in that children at an immature stage of development would be expected to perform better on forms which occur more frequently in their speech input than those which occur less frequently (because all three stages in learning how to use a morpheme require extensive exposure to the morpheme, and a child at a given stage of development will have had more exposure to high-frequency than low-frequency forms). The third effect we’d expect to find is a complexity effect, in that analysing the grammatical properties of a morpheme is going to take longer if the morpheme is a complex one encoding several features than if it is a simple one encoding a single feature. I shall use the informal term partial score to mean ‘the score I arrived at on the basis of the partial set of data which I looked at in the relevant section’. 223 97 I leave you to ponder on the possible significance of the above paragraph (and the wider discussion in section 3.2 of chapter 9) for how you evaluate the extent to which your research results are compatible with the Perceptual Deficit model. If you are looking for a possible frequency effect, you might like to bear in mind the results I obtained from looking at child-directed parental speech on 20 of the Abe files on the CHILDES data-base: in around 3 hours of conversation with him, Abe’s mother and father between them produced 144 tokens of progressive {ing} on main verbs (including 15 tokens of gonna), 91 tokens of 3SgPres {s} on main verbs, and 61 tokens of the regular past-tense affix {d} – along with 86 tokens of irregular past-tense main verbs (including 13 tokens of fell, 10 of went, 8 of ate, 7 of made and 6 of said). Now, while these figures are clearly based on a very small sample, they at least give us some idea of the likely relative frequency of particular inflected forms in parental speech to children. 3.3 Evaluation of the Rule Deficit model The Rule Deficit model claims that SLI children are unable to acquire regular morphological rules (like the present-tense s-rule, the past tense d-rule and the progressive ing-rule in (1) in §1.2), and that the only way they can acquire inflected forms (including s-forms) is by memorisation. Since memorisation (and the ability to retrieve a memorised form) improves with increased exposure, we’d expect to find a correlation between the suppliance rate for individual inflected word-forms and the frequency of the relevant form (e.g. that an SLI child at a given stage of development might achieve 80% suppliance of a high-frequency form, 50% suppliance of a medium-frequency form, and 20% suppliance of a low-frequency form). A second frequency effect predicted by Gopnik and Crago is SLI children will have particular problems in acquiring an individual inflected form that is less frequent than the corresponding bare form: for example, could it be that one reason why JC uses the bare form like in contexts where adults use the inflected (third person singular present tense) s-form likes is that like is 33 times more frequent than likes? So, the first thing you need to do is to look at is the extent to which you find any evidence of frequency effects. For example, could the reason why JC achieves 100% suppliance of progressive {ing} and 0% suppliance of 3SgPres {s} be that the ing-forms he uses have a much higher frequency of occurrence in adult English than the s-forms of verbs he uses in 3SgPres contexts? To answer this question, you could go to an American English frequency dictionary like Carroll (1971), and look at the frequency of occurrence of each of the progressive ing-forms JC produces, and of the present-tense s-forms of each of the verb that JC uses in a 3SgPres context224. If there is no such frequency effect (i.e. if it simply isn’t the case that the relevant ing-forms are far more frequent than the relevant s-forms), you might want to consider whether JC’s performance on ing-forms and s-forms of main verbs could be argued to be more consistent with an alternative rule-based account which supposes that he has acquired the regular progressive ing-rule, but has not acquired the regular 3SgPres s-rule. In other words, JC may have acquired the defective (i.e. incomplete) set of regular morphological rules shown below: (6) A regular verb carries the suffix {d} if past225 {ing} if progressive or gerund {ø} otherwise a defective rule system such as the following: If JC has indeed acquired the progressive ing-rule, this would falsify Gopnik and Crago’s claim that SLI children are incapable of acquiring any regular morphological rules. But if JC has not acquired the 3SgPres s-rule, it would suggest that we should revise the Rule Deficit theory so as to hypothesise that SLI 224 Carroll gives the following frequency figures (per million words) for relevant -ing forms (and the corresponding bare forms) in adult English: going = 2832 (go = 5388); being = 2092 (be = 60852); making = 1408 (make = 8333); doing = 927 (do = 12695); moving = 871 (move = 1592); taking = 719 (take = 4089); talking = 613 (talk = 1133); standing = 575 (stand = 1081); saying = 524 (say = 3916); flying = 508 (fly = 785); watching = 443 (watch = 969); eating = 419 (eat = 1616); leaving = 301 (leave = ???); falling = 239 (fall = 824); cooking = 212 (cook = 265); crying = 164 (cry = 327); digging = 124 (dig = 181); swinging = 108 (swing = 189); laying = 54 (lay = 54); pretending = 46 (pretend = 115); grabbing = 13 (grab = 73). The corresponding frequency figures (per million words) for s-forms of verbs used by JC in adult English are given in the previous chapter. 225 There are insufficient relevant examples in the corpus to be sure whether JC makes productive use of regular perfect and passive participle d-forms, so I have not included these here. 98 children are slow rather than unable to acquire regular morphological rules, and may go through a stage where they have acquired some but not all regular morphological rules (so that e.g. JC is at a transitional phase where he has acquired the ing-rule but not the s-rule). You also need to discuss how to account for JC’s performance on main verbs in past tense contexts. The partial results I reported earlier suggest that JC sporadically marks past tense in obligatory contexts (around a third of the time). One possible account of this might be that he has not yet acquired the regular past tense d-rule, but has memorised individual past tense forms, and sometimes manages to retrieve them (but sometimes doesn’t, instead using a bare form). If so, we’d expect to find a frequency effect for both regular and irregular past tense forms. But an alternative possibility is that he has indeed acquired the regular past-tense d-rule, but is in the early stages of learning to use it and so (since learning to use a rule requires extensive practice) only manages to apply it some of the time (using a bare verb-form by default when he fails to apply the rule): irregular verbs would be learned by memorisation on this account. If he has indeed acquired the regular past tense d-rule (and is in the early stages of learning to apply it), we’d expect to find a frequency effect for irregular past tense verb forms, but not for regulars. You should look at the discussion in section 2.3 of chapter 8 for how to test for frequency effects. You might also want to look at whether JC performs better on regular than irregular pasts, and the possible implications of your findings. You also need to discuss what these two alternative accounts of his performance on past-tense main verbs (relating to whether he has or hasn’t acquired the past tense d-rule) would predict about whether he will or won’t produce over-regularised or novel past tense forms, and whether you have any evidence from the JC corpus which you can use to test this prediction. 3.4 Evaluation of the Agreement Deficit model The core assumption of the Agreement Deficit model is that SLI children have problems in acquiring uninterpretable agreement features (but not in acquiring interpretable features). The research hypothesis which this gives rise to is that SLI children are expected to perform well on inflected forms which encode only interpretable features (like progressive forms, and past-tense forms), but much worse on forms which encode uninterpretable agreement features (like present-tense s-forms). My own partial results (to the effect that JC shows 100% suppliance of progressive forms, 45%/27% suppliance of correct regular/ irregular past-tense forms, and 0% suppliance of 3SgPres s-forms) appear to be partly consistent with what the model predicts, but raise the question of why JC should perform so much better on {ing} than on past tense forms? Can you think of possible reasons for why this might be? 3.5 Evaluation of the ATOM model The ATOM model claims that SLI children have particular problems in marking tense and agreement, and sometimes omit either or both of these features on verbs in finite contexts (i.e. in contexts where adults would use a verb which is marked for both tense and agreement). ATOM also assumes that case is tied up with agreement, and that SLI children use correctly case-marked forms when they mark agreement, and default (accusative) forms when they fail to mark agreement. Since progressive {ing} marks neither tense nor agreement, ATOM seemingly predicts that SLI children should perform well on this morpheme – and my partial score of 100% suppliance of progressive {ing} by JC in obligatory contexts would seem to bear out this prediction (though leaves unanswered the important theoretical question of why SLI children should have problems marking tense but not aspect, since both are interpretable features. Can you think of reasons why this should be the case?) In relation to testing the predictions which ATOM makes about how SLI children treat main verbs (and their subjects) in 3SgPres contexts, see the discussion of main verbs in section 3.5 of chapter 9. On the question of how to test the predictions made by ATOM about how SLI children treat main verbs (and their subjects) in past-tense contexts, see the discussion in sections 2.4 and 3.6 of chapter 8. 99 Chapter 4. Summary and Conclusions (about 15% of your overall study) 4.1 Summary of research hypotheses Begin this chapter with a section in which you provide a brief summary of the models of SLI and research hypotheses which you outlined in chapter 1. 4.2 Summary of research findings In this section, briefly summarise the main research findings you obtained in chapter 2 4.3 Summary of evaluations In this section, provide a brief summary of your evaluation (in chapter 3) of the relative strengths and weaknesses of each of the theories of SLI you are testing, viewed from the perspective of how well they account for your own research findings. 4.4 Overall conclusions In this (the most important) section of your chapter, you need to give your considered final verdict on which of the models you have looked at best accounts for your own research findings. If a particular model doesn’t account for (some of) your findings, can it be modified in some way which would make it compatible with your findings? If not, and if there is no one model of SLI which accounts for all your research findings, does this take you towards a composite model which sees SLI as involving multiple impairments, rather than a single type of impairment? (For my suggestions about what such a composite model might look like, since section 4.4 in the previous chapter.) To what extent (and precisely how) would such a composite model account for your research findings? Be particularly circumspect with your conclusions: these are usually the weakest point in student work, and could devalue your overall project. 5. Appendices After your conclusions, include as an Appendix any lists of sentences which provide the raw data from which you computed the figures for various tables included in the main body of your project 6. List of references After any Appendices, include a list of works (arranged alphabetically by author and date) which you have cited in your project. Use the standard author-date system to refer to relevant works in the main body of your text (e.g. set out in the same way as the references in section 12 of this coursebook). See the departmental handbook on how to set out references. 100 11: Empirical study III: Acquisition of subject case-marking in English In this chapter, I look at how to undertake an empirical study of The acquisition of the case-marking of subjects in English by a 4-year-old child with SLI. Your study might be organised as follows. 1. Background (about 25% of your overall study) 1.1 Introduction Give brief details (in a paragraph or two) of the kind of developmental disorder which SLI involves (summarised on p.4 of this book: see Bishop (1997), Leonard (1998), and the collection of papers in Bishop and Leonard (2000) and Levy and Schaeffer (2003) for more detailed discussion of diagnostic criteria for SLI), pointing out that various aspects of grammar are reported to be impaired in SLI children, including case-marking (in children under 7-8 years of age, at least). But the pattern of case errors reported in the SLI literature is far from random. For example, Loeb and Leonard (1991) and Bishop (1994) reported that SLI children almost invariably assign correct (accusative) case to objects, but make errors with the case-marking of subjects (using accusatives in contexts where adults require nominatives). Work by Schütze and Wexler (e.g. Wexler 1994; Schütze and Wexler 1996; Schütze 1997; Wexler 1999) on normally developing children and by Wexler, Schütze and Rice (1998) on SLI children has argued that the subject case-errors made by normally developing and SLI children alike are the consequence of children going through an Optional Infinitive/OI stage (or, in the case of SLI children, an Extended Optional Infinitive/EOI stage) during which they sometimes fail to mark either tense or agreement on verbs in finite contexts. In your project, you are aiming to test two different accounts of subject case errors developed within the framework of the (E)OI model – one (outlined in Bromberg and Wexler 1995) which sees subject case errors as the consequence of a tense deficit, and the other (outlined in Wexler, Schütze and Rice 1998) which sees subject case errors as the consequence of an agreement deficit. Your aim is to undertake a small-scale empirical study designed to evaluate these two accounts of subject case errors, by looking at the case-marking of subjects in nominative contexts by a four-year-old American boy with SLI, known as JC. Provide brief details of JC’s background and the transcripts you are using (which you can find at the beginning of chapter 13). You’re going to begin by briefly looking at subject casemarking in unimpaired (adult) grammars in the next section. 1.2 Case-marking of subjects in unimpaired (adult) grammars Sabine Iatridou (1993) argues that there is parametric variation between languages with respect to how nominative case-marking works. In languages like Modern Greek (she argues), nominative case is correlated with tense, in the sense that the subject of a tensed verb (i.e. one morphologically marked for present or past etc. tense) is assigned nominative case. By contrast, in languages like Classical Greek, nominative case is correlated with agreement, in the sense that the subject of an agreeing verb (i.e. one which agrees in person and number with the subject) is assigned nominative case. Iatridou’s research raises the question of whether tense or agreement is responsible for nominative case assignment in English. In principle, either analysis would appear to work for English, because finite verbs with nominative subjects in English typically inflect for both tense and agreement: for example, in He is lying the auxiliary is has a nominative subject he, but because is carries both (present) tense and (third person singular) agreement features, it could in principle be either tense or agreement (or a combination of the two) which is responsible for assignment of nominative case to the subject he. An additional complication is that when a subject does not fall within the domain of any case assigner, it is assigned default case – this being accusative in English. Hence, in a so-called ‘Mad magazine’ sentence like Me be disloyal to the party? Never! the subject pronoun me cannot be assigned nominative case because the verb be is an infinitive form which carries neither tense nor agreement. Accordingly, the subject is assigned accusative case by default (i.e. by virtue of being in a position where it would otherwise not be assigned any case at all). For more detailed discussion, see chapter 6. 101 1.3 The Extended Optional Infinitives model of SLI Wexler (1994) argued that normally developing children go through an Optional Infinitive/OI stage (which they usually grow out of by the time they reach 4 years of age) during which they alternate between producing inflected finite verbs and bare infinitives in finite contexts (i.e. in contexts where adults would use a finite verb inflected for tense and agreement). Hence, in reply to a past tense question like What did Daddy do yesterday? a child at the OI stage would alternate between using a finite verb like played (as in Daddy played tennis) and an uninflected infinitive like play (as in Daddy play tennis). In early version of the OI model, Wexler argued that children’s bare infinitives (in finite contexts) arise because children sometimes fail to mark tense on verbs in obligatory contexts. Bromberg and Wexler (1995, p.223) maintain that tense is responsible for nominative case assignment in English: if so, the subject of a tense-underspecified verb will not be able to be assigned nominative case (because only a tensed verb can assign nominative case to its subject), and so will be assigned accusative case by default instead. This predicts that (in finite contexts) children at the OI stage will alternate between producing structures containing a tensed verb with a nominative subject (as in He played tennis) and structures containing a tenseless (bare, uninflected, infinitive) verb with a default accusative subject (as in Him play tennis). In a revision to the earlier version of the OI model, Schütze and Wexler (1996) argued that the bare infinitive verb-forms produced by children at the OI stage can result from omission of either tense or agreement (or both). They posited that agreement is responsible for nominative case assignment in English, and that (in consequence) default accusative subjects arise when a verb is underspecified for agreement (so that a child at the OI stage may produce a structure such as Him played tennis if the verb played is specified for tense but not specified for agreement). Wexler, Schütze and Rice (1998) argue that SLI children also go through an OI stage, but that this typically lasts twice as long (until around 8 years of age) as for normally developing children: hence they refer to it as the Extended Optional Infinitive/EOI stage. They follow Schütze and Wexler (1996) in positing that bare infinitives in finite contexts arise via underspecification (= omission) of either tense or agreement (or both), and for this reason, they refer to their model as the Agreement and Tense Omission Model/ATOM. They too assume that accusative subjects arise from failure to mark agreement on verbs, resulting in assignment of default accusative case to the subject. You can conclude this section by saying that what you are setting out to do in your project is test the two different (E)OI accounts of the subject case errors made by SLI children in finite contexts – one which sees them as resulting from omission of tense-marking on verbs, and the other which sees them as resulting from omission of agreement. In the next section, you’re going to look at the predictions made by the tense-deficit account of the (E)OI stage about the case-marking of subjects in a range of different types of finite context, and in the following section you’re going to look at the predictions made by the agreement-and-tense deficit (ATOM) model. 1.4 Patterns of subject case-marking predicted by the Tense Deficit model Under the tense-deficit account, we expect a child at the (E)OI stage to produce two different types of sentence structure in contexts where adults use a past-tense main verb (e.g. Daddy played with me). One possibility would be for the child to correctly mark the verb for past tense and (because tense triggers nominative case assignment) assign nominative case to the subject (resulting in He played tennis); the other would be for the child to fail to mark tense on the verb, so resulting in in structures like Him play tennis (with the verb not carrying the past tense suffix {d} because it is tenseless, and the subject carrying default accusative case because a tenseless verb cannot assign nominative case to its subject). Thus, the child is predicted to produce sentences like He played tennis and Him play tennis (but not *Him played tennis or *He play tennis) in such contexts. Now consider what would be expected to happen in contexts where adults would produce a sentence containing a third-person-singular present-tense (3SgPres) main verb (e.g. Daddy plays tennis). If tense and agreement are marked (and the 3SgPres affix {s} has been acquired), the child will be predicted to use a nominative subject (because tense in marked) and an s-inflected verb (e.g. He plays tennis). But if tense 102 is not marked, the verb will lack the {s} affix (because this can only be used when both tense and agreement are marked) and the subject will be assigned accusative case by default (because only a tensed verb has a nominative subject) – and so the child will say Him play tennis. Thus in 3SgPres contexts, the child is predicted to say He plays tennis and Him play tennis, but not *Him plays tennis or *He play tennis. In contexts where adults would produce a bare present-tense main verb with a non-3Sg subject (i.e. a subject which is not third person singular), children at the (E)OI stage are expected either to mark tense and use a nominative subject (as in I play tennis), or fail to mark tense and use a default accusative subject (as in Me play tennis). Of course, tense-marking in such cases would not be directly visible on the verb. Now consider what is expected to happen in contexts where an SLI child produces a structure containing a finite auxiliary (like am/are/is/was/were/does/do/did/has/have/had/will/would/can/could etc.). Since auxiliaries are all tensed (e.g. can is a present-tense form and could a past-tense form), and tensed verbs require a nominative subject, the prediction is that all auxiliaries used in finite contexts will have nominative subjects (hence an SLI child is predcted to say I can swim and not *Me can swim). Finally, consider what is expected to happen in auxiliary-omission structures (i.e. structures in which children have omitted a finite auxiliary which would be obligatory in the corresponding adult sentence). If (as claimed by Bromberg and Wexler 1995, p.223) auxiliary omission is the consequence of tense omission, such sentences will be tenseless and so have accusative subjects by default – so that children are predicted to say e.g. Him playing tennis but not *He playing tennis. 1.5 Patterns of subject case-marking in finite contexts predicted by the ATOM model The agreement-and-tense deficit account assumed in the ATOM model makes subtly different predictions (from those made by the tense deficit model, outlined in §1.4) about the case-marking of subjects by children at the (E)OI stage. Since the ATOM predictions are outlined at length in chapter 6 of this coursebook, I will not repeat the relevant material here. 1.6 Research hypotheses being tested In this final section, you should summarise succinctly (perhaps in a neat tabular form) the range of structures which children at the (E)OI stage are predicted to produce and not produce – and highlight the differences in predictions made by the two accounts of the (E)OI stage which you are focussing on. 2. Research results (about 25% of the overall study) 2.1 Introduction Begin by noting that in this chapter/section you are setting out to test the predictions made by the two alternative (E)OI accounts of subject case-marking which you outlined in §1.4 and §1.5. You are going to do this by looking at how JC case-marks subjects in a variety of different types of finite context. Because you are concerned with his use of nominative and accusative subjects, you are only going to include structures containing an unambiguously nominative pronoun like I/we/he/she/they or an unambiguously accusative pronoun like me/use/him/her226/them (I’ll call such pronouns unambiguous). You are only going to be concerned with overt subjects (not null subjects), for the obvious reason that you are looking at unambiguous subject pronouns, and there is no way of knowing what case (if any) null subjects have. In the various sections below, you are going to look at how JC case-marks (unambiguous) subjects in a range of different types of structure which he produces in finite contexts. 226 In principle, her is ambiguous between being an accusative or genitive pronoun, but since JC makes extensive use of accusative subjects (but not genitive subjects), we can assume that her subjects are accusative. 103 2.2 JCs case-marking of subjects with agreeing tense-marked auxiliaries In (1) below, I have listed all the examples which occur in the JC corpus of an unambiguous pronoun which occurs as the subject of an auxiliary227 (like am/are/is/was) which is overtly inflected for both tense and agreement (in that e.g. (a)m is a first person singular present tense form of BE). The relevant pronoun is italicised in each case. (1) I he they List of unambiguous subject JC uses with auxiliaries inflected for tense and agreement 86. I’m cooking something for dinner 162. Cause I’m bigger than him 164. I’m bigger than him 186. I’m gonna have to pick it up first 201. I’m not scare of them 363. I’m gonna be so proud 320. What’s228 I talking about? 56. He’s sick 155. He’s funny 173. He’s sad cause he can’t go 188. He’s digging up dirt 59. But, he’s229 not have no money 165. (Th)ey are straps On the basis of the data in table (1), you can then calculate the percentage of nominative and accusative subjects which JC uses with agreeing auxiliaries – a straightforward task. 2.3 JCs case-marking of subjects with ambiguous auxiliaries In (2) below, I’ve listed all examples of unambiguous pronouns used as subjects of what Wexler, Schütze and Rice (1998) call ambiguous auxiliaries (e.g. can/can’t/could/don’t230/didn’t) – that is, auxiliaries which are clearly marked for tense, but where it’s impossible to tell whether they are marked for agreement (and hence agree invisibly with their subject) or not. (2) I me we he him her List of unambiguous subject pronouns used by JC with (underlined) ambiguous auxiliaries 1. After that I can do that 151. I can make a big big man 194. Ah, so happy I can get out of them fish 203. I can make see my shadow 225. I can fall 167. I try to take it off, but I can’t put on 168. I can’t put this on 15. I don’t wanna play with that 19. I don’t know 61. I don’t have a doctor set 129. I don’t know 240. I don’t know where her can cook 243. I don’t know what he saying 248. I don’t, I like tea 222. I’n231 see that one, cause that one is very good 10. Me can’t back home to go shopping 70. Me can have this 22. Me don’t know 84. Me don’t have a cat on a bed 192. We can do all over again 85. He can play with that 181. He can fly 182. He can do it 183. He can fly cause he got these wings 184. He can pretend fly 351. He can eat it 173. He’s sad cause he can't go 176. And he can’t go and he family... die 115. No, he could burn heself 63. He don’t have this jacket 294. Why he don’t have a nose? 11. Why him don’t have eyes? 147. Then her can make a pretty one 148. No, her can put up here 238. Her can cook something 240. I don’t know where her can cook On the basis of the list in (2), you can calculate the percentage of nominative and accusative subjects which JC uses with ambiguous auxiliaries. 227 This term (as used here) includes all uses of BE, since (in all uses) BE behaves like an auxiliary in e.g. undergoing inversion in questions (cf. Are you ready?) and being negated without the use of DO (cf. He isn’t ready). 228 The form ’s here is arguably a contracted form of was (cf. What was I talking about?) 229 The form ’s here is arguably a contracted form of does. 230 Bear in mind that in colloquial American English, don’t is used with all types of subject, including third person singular subjects (so that in numerous pop-songs we find the line He don’t love me no more, rather than the more formal style He doesn’t love me any more). JC doesn’t produce doesn’t at all in the corpus. 231 Taken by the person who did the transcription to be a contracted form of didn’t. 104 2.4 JCs case-marking of subjects in null-auxiliary structures In (3) below, I have listed all the unambiguous-subject structures produced by JC whose adult counterpart would contain a finite auxiliary, but which JC produces without any overt auxiliary232: List of unambiguous subject pronouns use by JC in null-auxiliary structures233 166. I got on my shirt and have trouble doing my back 220. I got a new Barney 223. I got a different Barney 245. I got a train 334. But, I got another one 365. I got my hair from barber 322. Then, I eating food 95. I hear myself again? 201. When I be bigger234, I’m not scare of them 8. Me bigger than Gio and him 9. Me bigger him 46. Me too tired 28. Me talking bout... me 89. Me making nice and neat 96. Me watching about it 150. Me making a car 237. Me making hot dogs 33. Me said, me gotta hurry up and go up 271. Me got Ms. Peggy speech teacher 286. And then it scared mom, so we gonna put him to trouble 333. We making books we 252. But we got two more 272. We got a lotta fish for everyone 369. We got some new pictures 17. He happy 76. He under the table 175. And he sad cause he crying he 88. He making a mess 108. This one, he cooking up a hot dog 178. He crying, he crying 204. He flying 243. I don’t know what he saying 287. And then he be trouble235 317. How he gonna eat me up? 318. He grabbing a lollipop 377. He taking a lollipop 378. He gonna bite you 54. But he not there 217. He not real 183. He can fly cause he got these wings 221. He got old one 60. Her pretending to being a doctor 77. Her laying 195. Her standing and her see herself her 302. Her eating a cookie 149. Her sad 57. Nuh uh, This girl is...her not 145. Why her need this? them 374. Why them both have pinchers? (3) I On the basis of the data in the list in (3), you can calculate the percentage of nominative and accusative subjects which JC uses in null-auxiliary structures. 2.5 JCs case-marking of subjects in past-tense main-verb contexts In (4) below, I have listed all the unambiguous-subject structures produced by JC in contexts where adults would use an (underlined) verb in the past tense form. (4) I me we he 232 List of unambiguous subject pronouns used by JC in past-tense main-verb contexts 198. Long time ago I have a big eye 230. I see clown at a post office 236. I never saw one of these stove 321. Long time ago, I go camp and hiking at the same time 323. And I eat at hiking 339. I forgot 16. Me used to have a dog, but somebody take it away 23. Me got one from Michael 27. Me got chicken pox 32. Me fall asleep on the couch 33. Me said, me gotta hurry up and go up 81. Like me see on the TV 103. Me just jumpovered it 327. Then me said, oh! 328. Then me take it xxx 329. Then me go camping 330. Me eat all our food 229. We see clown at...umm... 283. And then her put on the floor, and we scare her 324. And then at hiking, I xxx a picnic, so we eat 5. He see snow on he chimney 105. He shoveled someone else 112. He burn heself here 113. He eat it 114. No, took it off of...then he eat it 125. I think this, he...umm, oh, he dump it 126. He shoveled him truck 132. And then he drived away 127. And then he dump it 130. He shoveled him truck 131. Then he dump it 133. Because, he want to put it 144. Then, he knocked him window 174. He family, he lost he family 179. He lost him duck 193. Oh, he caught me 211. And then, he scare them and said ha, ha, ha 213. Then, he talk to himself 232. He give a plane balloon 281. He say, put it down 298. I know, he wanned to go and drop it 300. He jumped out 301. He bit me 316. He try to eat me up 379. He cut me Recall that it is being assumed here that BE is an auxiliary in all its uses, for reasons given earlier. The idea behind this term is that in contexts where an adult would use an auxiliary structure like He’s working (which contains the overt auxiliary (i)s), JC may produce a structure in which the auxiliary is null (i.e. ‘silent’) 234 There may be a missing will auxiliary here – though you may prefer to exclude the example as indeterminate. 235 The missing auxiliary here is presumably will. 233 105 her them 268. Her make it for Ms Peggy a long time ago 277. Her give me dad a lobster, a two lobster 282. And then her say, Ahhh! 283. And then her put on the floor, and we scare her 284. Her say, ahh it's moving 303. Then, her drink some water 311. Her have a snake in the sink 314. Then her got hurt 231. Them have a party, and clown give me a balloon 285. And then, them cook them up 366. But them cut my hair real tiny On the basis of the data in the list in (4), you can calculate the percentage of nominative and accusative subjects which JC uses in past-tense main-verb contexts (i) with tensed verbs, and (ii) with tenseless (bare) infinitive verbs. (Of course, you will have to exclude verb-forms which are ambiguous between being past tense forms and infinitive forms from these two counts.) 2.6 JCs case-marking of subjects in present-tense main-verb contexts In (5) below, I have listed all the unambiguous-subject structures produced by JC in contexts where adults would use an (underlined) main verb in an appropriate present-tense form. (9) I JC’s use of unambiguous subject pronouns in present tense main verb structures 6. When I go iceskate me fall. 37. I just have a garbage truck, not a monster 92. I make some peppers 93. I win 119. I eat a lot of ketchup 153. I see her and you 163. I have to do it all by myself, cause, cause... 167. I try to take it off, but I can't put on 199. I think it's a ghost 202. I see he shadow 219. I have a new Barney 227. I wanna play some games 234. I wanna play a stove 235. I like it, cause, cause, I wanna play 248. I don't, I like tea 249. I like warm tea 250. I have tea at boy scout 257. I put this and this 265. I remember 295. Ah I remember this 296. I remember that thing 298. I know, he wanned to go and drop it 323. I say, and I eat at hiking 331. I mean this much 338. Now I do all by myself 359. Then, I grab my one 361. Then, I eat it after lunch 362. I need ten stickers 364. I know her 371. I know these ones 2. When me go outside to play me go like that 3. Me go like everywhere 6. When I go iceskate me me fall 7. Me cry 12. Me never have them real big 13. Me never take a shower 14. Then, me no have to go bath 21. Me have different puzzle 35. Come up there, then me sleep up there 36. Me fall asleep up there 47. Me remember some of that 49. Me wanna hurt somebody 50. Me wanna point it and hurt somebody 74. Me know how to do it 91. Me put some pepper here 118. Me like ketchup 142. Me go beach not far away 143. Hey, me go faraway beach 152. Me see her and you 270. Me know, but my...me get two cause... 295. Me remember 310. Me remember her house snake 319. Me remember at school... 350. We just give to Easter Bunny we 355. We take one at a time 64. He only have a coat 65. Now he have them two 67. He have a doctor 156. He have he hats he on 352. He hafta 55. He like Danny talking like that 116. When he hold here 356. He put in a box with lots different and jelly bean 357. Then he bring it 44. When him crack tiny pieces up, and then put xxx 376. He...him go first him 195. Her standing and her see herself 349. Her use with a green cutter thing her 370. Her need the camera to put in a locker 137. That why them put a lot of sand 138. Them put all over 373. Them both have pinchers them On the basis of the data in the list in (4), you can calculate the percentage of nominative and accusative subjects which JC uses in present-tense main-verb contexts. Although one would normally compute separate figures for verbs with 3Sg and non-3Sg subjects, there seems to be little point in the case of JC because (as discussed in chapter 9) he has a morphological deficit and has not acquired the 3SgPres morpheme {s}, with the consequence that all his present tense verb-forms are bare – even those with 3Sg subjects. 106 2.7 Summary of research results In this section, you should succinctly summarise your research results – perhaps in tabular form (though if you do this, make sure you explain what each part of the the table represents). 3. Analysis of research results (around 35% of your overall study) 3.1 Introduction Begin with an introduction saying that what you are aiming to do in this section/chapter is evaluate the extent to which the research findings that you reported in section 2.7 are consistent (or inconsistent) with the tense-deficit account of the (E)OI stage on the one hand, and the ATOM (agreement-and-tense deficit) account on the other. You’ll look at each of your major research findings in a different section below, and evaluate the extent to which each of the two accounts is (or is not) compatible with your findings. In the final section, you’ll provide an overall evaluation of which of the two accounts is best able to explain the overall pattern of case-marking you find in the full range of structures produced by JC in finite contexts. 3.2 Evaluation of accounts of JCs case-marking of subjects with agreeing tensed-marked auxiliaries Briefly summarise the predictions made by each of the two accounts, remind the reader of the research results you obtained in §2.2, and provide an evaluation of the extent to which each account is compatible with your results. 3.3 Evaluation of accounts of JCs case-marking of subjects with ambiguous auxiliaries Briefly summarise the predictions made by each of the two accounts, remind the reader of the research results you obtained in §2.3, and provide an evaluation of the extent to which each account is compatible with your results. 3.4 Evaluation of accounts of JCs case-marking of subjects in null-auxiliary structures Briefly summarise the predictions made by each of the two accounts, remind the reader of the research results you obtained in §2.4, and provide an evaluation of the extent to which each account is compatible with your results. 3.5 Evaluation of accounts of JCs case-marking of subjects in past-tense main-verb contexts Briefly summarise the predictions made by each of the two accounts, remind the reader of the research results you obtained in §2.5, and provide an evaluation of the extent to which each account is compatible with your results. 3.6 Evaluation of accounts of JCs case-marking of subjects in present-tense main-verb contexts Briefly summarise the predictions made by each of the two accounts, remind the reader of the research results you obtained in §2.6, and provide an evaluation of the extent to which each account is compatible with your results. 3.7 Overall evaluation of the two accounts of the (E)OI stage In this final section, begin by providing an overall evaluation of the extent to which the tensed-based account of nominative case assignment handles the results you reported in §3.2-§3.6. Then go on to evaluate the extent to which the agreement-based account of nominative case assignment handles the same results. Say which account seems to be superior to the other – and in what respects. 107 Chapter 4. Summary and Conclusions (about 15% of your overall study) 4.1 Summary of research hypotheses Begin this chapter with a section in which you provide a brief summary of the two different versions of the EOI model of SLI – the Tense Deficit and ATOM (Agreement-and-Tense Deficit) models, and what each predicts about the case-marking of subjects. 4.2 Summary of research findings In this section, briefly summarise the main research findings you obtained in chapter 2 4.3 Summary of evaluations In this section, provide a brief summary of your evaluation (in chapter 3) of the relative strengths and weaknesses of the Tense Deficit and ATOM accounts of SLI, viewed from the perspective of how well they account for JC’s case-marking of subjects. 4.4 Overall conclusions In this (the most important) section of your chapter, you need to give your considered final verdict on which version of the EOI model best accounts for your own research findings. Does one of the two accounts handle a much wider range of structures than the other? What possible drawbacks are there to either or both of the accounts? For example, does JC perform better on some nominative pronouns than others, and if so what might the sigificance of this be, and how might we account for it – e.g. is the relative frequency of different nominative pronouns in adult English a possible factor?236 (You will find some critical reflections on ATOM in my Children’s English coursebook (in chapter 6 on Underspecification) on http://courses.essex.ac.uk/lg/lg620 (under acquisition coursebook). Be particularly circumspect with your conclusions: these are usually the weakest point in student work, and could devalue your overall project. 5. Appendices After your conclusions, include as an Appendix any lists of sentences which provide the raw data from which you computed the figures for various tables included in the main body of your project 6. List of references After any Appendices, include a list of works (arranged alphabetically by author and date) which you have cited in your project. Use the standard author-date system to refer to relevant works in the main body of your text (e.g. set out in the same way as the references in section 12 of this coursebook). See the departmental handbook on how to set out references. Carroll’s (1971) frequency dictionary shows that (in adult American English), the frequency of unambiguously nominative pronouns per million words is: he = 46249; they = 27620; I = 25932; we = 16452; she = 13653. 236 108 12: List of references Abney, S.P. (1987) The English Noun Phrase in Its Sentential Aspect, PhD diss., MIT. Arthur G (1952) The Arthur Adaptation of the Leiter International Performance Scale, Stoelting, Chicago Bernstein Ratner N (1984) ‘Patterns of vowel modification in mother-child speech’, Journal of Child Language 11: 557-558 Bishop DVM (1994) ‘Grammatical errors in specific language impairment: Competence or performance limitations?’, Applied Psycholinguistics 15: 507-550 Bishop, DVM (1997) Uncommon Understanding: Development and Disorders of Language Comprehension in Children, Pychology Press, Hove Bishop D & Edmundson A (1987) ‘Specific language impairment as a maturational lag: Evidence from longitudinal data on language and motor development’, Developmental Medicine and Child Neurology 29: 442-459 Bishop DVM & Leonard LB (eds) Speech and Language Impairments in Children: Causes, Characteristics, Intervention and Outcome, Psychology Press, Hove. 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Gopnik M (1990) ‘Feature blindness: A case study’, Language Acquisition 1: 139-164 Gopnik M & Crago MB (1991) ‘Familial aggregation of a developmental disorder’, Cognition 39:1-50 Guilfoyle E (1984) ‘The acquisition of tense and the emergence of lexical subjects in child grammars of English, McGill Working Papers in Linguistics 2: 20-31 Hurst J, Baraitser M, Auger E, Graham F and Norell S ‘An extended family with an inherited speech disorder’, Developmental Medicine and Child Neurology 32: 347-355. Iatridou S (1993) ‘On nominative case assignment and a few related things’, MIT Working Papers in Linguistics 19: 175-196 Johnson C et al (1999) ‘Fourteen-year follow-up of children with and without speech/language impairments’ Journal of Speech and Hearing Research 42: 744-760 Lai CS, Fisher SE, Hurst JA, Vargha-Khadem JA & Monaco AP (2001) ‘A forkhead domain gene is mutated in a severe speech and language disorder’, Nature 413: 519-523 Leonard LB (1989) ‘Language learnability and specific language impairment in children’, Applied Psycholinguistics 10: 179-202 Leonard LB (1992) ‘Specific Language Impairment in three languages: Some cross-linguistic evidence’, in P Fletcher and D Hall (eds) Specific Speech and Language Disorders in Children, Anetheium Press, San Diego, chapter 9. 109 Leonard, LB (1995) ‘Functional categories in the grammars of children with Specific Language Impairment’, Journal of Speech and Hearing Research 38: 1270-1283 Leonard LB, McGregor KK and Allen GD (1992) ‘Grammatical morphology and speech perception in children with specific language impairment’, Journal of Speech and Hearing Research 35: 1076-1085 Leonard LB (1998) Children with Specific Language Impairment, MIT Press, Cambridge Mass. 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Wexler K, Schütze C & Rice M (1998) ‘Subject case in children with SLI and unaffected controls: Evidence for the Agr/Tns Omission Model, Language Acquisition 7: 317-344. 111 13: Appendix (Transcripts of samples of the language production of a 4-year-old American boy with SLI) PROFILE OF THE BOY (KNOWN AS JC) JC is a white middle-class American boy from Western Massachusetts with white parents who speak Standard American English. When tested he had an average score in non-verbal intelligence, a moderately low score in verbal intelligence, moderately low scores in standard (TOLD-P237) tests of comprehension and expression, average receptive and expressive vocabulary, age-appropriate articulation skills, normal hearing acuity, and no known neurological or emotional problems. The JC corpus comprises 8 recordings of his spontaneous speech (each of roughly 10 minutes in duration) at ages 4;3.15, 4;4.20, 4;5.3, 4;5.14, 4;5.16, 4;5.23; 4;6.3, and 4;6.12. Information is provided in parentheses on the contexts in which some of the utterances produced by JC occurred, together with (in some cases) a gloss which represents the presumed adult counterpart. xxx marks an unintelligible stretch of speech. Recording 1: 10/1/94 age 4;3.15 1. After that I can do that 2. When me go outside to play me go like that 3. Me go like everywhere (‘I go like that everywhere’) 4. That me friend (‘That’s my friend’) 5. He see snow on he chimney (‘He saw snow on his chimney’) 6. When I go iceskate me fall (‘When I go ice-skating, I fall) 7. Me cry 8. Me bigger than Gio and him (‘I’m bigger that Gio and him’) 9. Me bigger him (‘I’m bigger than him’) 10. Me can't back home to go shopping 11. Why him don't have eyes? (‘Why don’t238 he have eyes?’) 12. Me never have them real big (‘I never have them really big’) 13. Me never take a shower 14. Then, me no have to go bath (‘Then I won’t have to go for a bath’) 15. I don't wanna239 play with that 16. Me used to have a dog, but somebody take it away Recording 2: 16/2/94 age 4;4.20 17. He happy (‘He’s happy’) 18. Now, going home cause it melted [describing picture] (‘He’s going home...’) 19. I don't know (reply to ‘What did you tell your mom?’) 20. Not like this (reply to ‘Do you have puzzles at home?’) 21. Me have different puzzle (‘I have a different puzzle’) 22. Me don't know (reply to ‘Who did you give candy to?’) 23. Me got one from Michael 24. Chicken pox, chicken pox 25. No, but chicken pox, mmm, itchy (reply to ‘Did you have chicken pox?’) 26. No, it a long time ago (‘No, it was a long time ago’) 27. Me got chicken pox 28. Me talking bout... (‘I’m talking about...’) 237 Test of Language Development-Primary, taken by children aged 4-8 years of age. This tests understanding and the use of spoken words, aspects of grammar and pronunciation. 238 In many (American and other) varieties of colloquial English, don’t is an invariable form like won’t, used with all kinds of subjects including third person singular subjects. Hence, numerous American pop songs contain the lament ‘(S)he don’t love me no more’ (rather than the Standard English counterpart ‘He doesn’t love me any more’). 239 In colloquial (esp. American) English, want to is often pronounced wanna, and wanted as wanned. In effectm the final –t of want in such forms is dropped. 112 29. How long the song gonna be on? (‘How long is the song gonna be on?’) 30. Why it not being on? (‘Why isn’t it on?’ – referring to tape recorder) Recording 3: 1/3/94 age 4;5.3 31. Play Nintendo (reply to ‘What did you do?’) 32. Me fall asleep on the couch (‘I fell asleep on the couch’) 33. Me said, me gotta hurry up and go up 34. It's a little bit night time 35. Come up there, then me sleep up there (‘(I) went up there, then I slept up there’) 36. Me fall asleep up there (‘I fell asleep up there’) 37. I just have a garbage truck, not a monster (reply to ‘Do you have a monster truck?’) 38. It don't have a mouth 39. But it a truck you dump dirt, and snow, and other stuff (‘It’s a truck where you...’) 40. You can put everything in there 41. When you dump it 42. Some put sand and bring it to a different stop 43. And put garbage in the machine 44. When him crack tiny pieces up, and then put xxx (‘When he breaks tiny pieces up...’) 45. Then dump into a truck again (‘Then dumps them into a truck again’) 46. Me too tired (‘I’m too tired’) 47. Me remember some of that 48. Look at last time 49. Me wanna hurt somebody [talking about truck again] 50. Me wanna point it and hurt somebody 51. It very sharp (‘It’s very sharp’) 52. It can hurt somebody 53. It can poke somebody 54. But he not there (‘But he’s not there’) 55. He like Danny talking like that (‘He likes Danny talking like that’) 56. He's sick 57. Nuh uh, This girl is...her not (reply to ‘I think this girl is pretending she’s a bus driver’) 58. But, he bus (= ‘her bus’) is over here (reply to ‘Do you think she is a real bus driver?’) 59. But, he's not have no money (‘But she doesn’t have any money’) 60. Her pretending to being a doctor [describing picture] 61. I don't have a doctor set 62. Me brother name Jack (‘My brother’s name’s Jack’) 63. He don't have this jacket 64. He only have a coat (‘He only has a coat’) 65. Now he have them two 66. Not this kind 67. He have a doctor 68. Just a doctor 69. Not a doctor, but... 70. Me can have this 71. All of these can be me (= ‘mine’), and you can find another one for him 72. That can be Giovanni (= ‘Giovanni's’) 73. Got a girl again 74. Me know how to do it 75. Is a dog under a table (‘It’s240 a dog under a table’ – describing a picture) 76. He under the table (‘He’s under the table’) It’s not clear what is represents here. For example, it may be an attempt as it’s in which the t is dropped in order to simplify the consonant cluster ts 240 113 77. Her laying (‘She’s lying down’) 78. It's a cat 79. Nuh uh, Baby can just jump out (reply to ‘That’s a baby bed’) 80. You need a baby cage, so you can't get out 81. Like me see on the TV (‘Like I saw on the TV) 82. And that's not for a baby, cause only for a cage 83. Make a baby can go in it (?= ‘They make it so a baby can go in’) 84. Me don't have a cat on a bed [referring to picture] 85. He can play with that 86. I'm cooking something for dinner 87. You have to drink it when you take the coffee up 88. He making a mess (‘He’s making a mess’) 89. Me making nice and neat (‘I’m making it/them nice and neat’) 90. Pour it here 91. Me put some pepper here 92. I make some peppers 93. I win (‘I am the winner’) Recording 4: 8/3/94 age 4;5.14 94. My hear myself again? (‘Can241 I hear myself again?’ – i.e. on the tape recorder) 95. I hear myself again? (reply to ‘What?’) 96. Me watching about it (reply to ‘Did you watch somebody brushing their teeth on TV?’) 97. No, somebody else taked it (reply to ‘Did your teacher take the TV into your room?’) 98. That because them mom don't let them (‘That’s because their mum doesn’t let them’ – reply to ‘Nobody could go outside because of the snow storm’) 99. But, me mom let (‘But my mum lets (me/us/them)’) 100. Them mom could let them play outside (‘Their mum could let them play outside’) 101. Somebody else asked my mom to play outside with them 102. No one shoveled it (reply to ‘Who shoveled the snow?’) 103. Me just jumpovered it (‘I just jumped over it’) 104. Me dad too (response to another child saying ‘Yeah, my dad’ in reply to ‘Nobody shoveled the snow?’) 105. He shoveled someone else [?= ‘He shoveled someone else’s (snow)’] 106. Who that? (‘Who’s that?’, looking at a picture) 107. This one 108. This one, he cooking up a hot dog (‘This one, he’s cooking a hot dog’) 109. And put buns on it, and ketchup 110. Ketchup and mustard 111. Ooh, that gross (‘Ooh, that’s gross’) 112. He burn heself here (‘He burned himself there’) 113. He eat it (interviewer replies ‘He ate it?’) 114. No, took it off of...then he eat it (‘No, he took it off of... then he ate it’) 115. No, he could burn heself (reply to ‘Could he hold the hot dog like that?’) 116. When he hold here (‘When he holds it here’) 117. Me daddy like mustard (‘My daddy likes mustard’) 118. Me like ketchup 119. I eat a lot of ketchup 120. Know? The teacher said when you eat a lot of food you got food in your mouth (‘Know what? The teacher said that when you eat a lot of food, you get food in your mouth’) 121. And it stick to you (‘And it sticks to you’) 122. You can't take it off 241 It may be that ‘Can I…’ got reduced to |kna I| and then |naI|, and this was then (mis-)transcribed as my. 114 123. Only you can brush your teeth very good (‘The only thing you can do is brush your teeth really well’) 124. And it's gonna be all gone (‘And then all the food will disappear’) 125. I think this, he...umm, oh, he dump it (‘I think this, he dumped it’) 126. He shoveled him truck (‘He shoveled it into his truck’) 127. And then he dump it (‘And then he dumped it’) 128. It's hard to find this 129. I don't know 130. He shoveled him truck (‘He shoveled it into his truck’) 131. Then he dump it (‘Then he dumped it’) 132. And then he drived away (‘And then he drove away’) 133. Because, he want to put it (‘Because he wanted to put it (somewhere)’ – reply to ‘Why did he do that?’) 134. So you don't want no ice to fall down 135. When you go on the sand you trip xxx 136. No ice can go underneath sand 137. That why them put a lot of sand (‘That’s why they put a lot of sand there’) 138. Them put all over (‘They put it everywhere’) 139. Then it can go under it 140. Then step on it, no ice (‘Then when you step on it, there’s no ice’) 141. What beach you going? (interviewer replies ‘Oh, far away’) 142. Me go beach not far away (‘I go to a beach not far away’) 143. Hey, me go faraway beach 144. Then, he knocked him window (‘Then he knocked on his window’) 145. Why her need this? (‘Why does she need this?’) 146. Oh, so for to stick in here (‘In order to stick it in here’) 147. Then her can make a pretty one 148. No, her can put up here (‘No, she can put it up here’) 149. Her sad (‘She’s sad’) 150. Me making a car (‘I’m making a car’) 151. I can make a big big man 152. Me see her and you (interviewer replies ‘What?’) 153. I see her and you 154. It's a plane 155. He's funny 156. He have he hats on (‘?= He has his hat(s) on’) 157. A girl hat (‘A girl’s hat’) 158. This is a girl and this is a boy Recording 5: 10/3/94 age 4;5.16 159. This is somebody else fishing (= ‘somebody else's fishing game’) 160. This is you? (‘Is this yours?’) 161. Now it's gonna be Matthew (= ‘Matthew’s turn’) cause, cause... 162. It's gonna be my (= ‘mine’, i.e. ‘my turn’), cause I'm bigger than him 163. I have to do it all by myself, cause, cause... 164. I'm bigger than him 165. (Th)ey are straps (reply to ‘What are those?’) 166. I got on my shirt and have trouble doing my back (‘I’ve got my shirt on and have trouble tucking the back of the shirt in’) 167. I try to take it off, but I can't put on 168. I can't put this on 169. But a T-shirt, can take it off (‘But a T-shirt, I can take it off’) 170. Long time ago you give me that first (‘A long time ago, you gave me that beforehand’ – reply to ‘I’ll give you the net after you catch a fish’) 115 171. It's swinging 172. Can't see it from here 173. He's sad cause he can't go 174. He family, he lost he family (‘His family, he lost his family’ – describing a picture) 175. And he sad cause he crying (‘And he’s sad because he’s crying’) 176. And he can't go and he family... (interviewer asks ‘What happened to his family?’) 177. Die 178. He crying, he crying 179. He lost him duck (‘He lost his duck’) 180. Why you put that toy way up there? 181. He can fly 182. He can do it 183. He can fly cause he got these wings 184. He can pretend fly (‘He can pretend to fly’) 185. All these fish can pretend fly 186. I'm gonna have to pick it up first 187. It's a farm 188. He's digging up dirt 189. Dirt is falling all over him 190. Can't do that Matthew! 191. Can do all over again (‘We can do it all over again’) 192. We can do all over again 193. Oh, he caught me 194. Ah, so happy I can get out of them fish 195. Her standing and her see herself (‘She is standing and she sees herself’ – describing picture) 196. This black shadow is her and her 197. It's her hair 198. Long time ago I have a big eye (‘A long time ago, I had a swollen eye’) 199. I think it's a ghost 200. It's not, imagination (‘It’s not, it’s imagination’) 201. When I be bigger, I'm not scare of them (‘When I’m bigger, I won’t be scared of them’) 202. I see he shadow (‘I can see his shadow’) 203. I can make see my shadow (‘I can make people see my shadow’) 204. He flying (‘He’s flying’) 205. It's a... 206. Ooh, this is a scary one 207. It's a owl 208. An owl did this with he eyes (= ‘his eyes’) 209. Is green (‘It’s green’) 210. And he, hooh, and someone look at there (= ‘looked up there’) and said ah! 211. And then, he scare (= ‘scared’) them and said ha, ha, ha 212. Very funny 213. Then, he talk (= ‘talked’) to himself 214. Some wake up middle of night (‘Some people woke up in the middle of the night’) 215. Then, when someone go down, and the owl scare them (‘When someone went downstairs, the owl scared them’) 216. It just pretend 217. He not real 218. Oh, that's different Barney 219. I have a new Barney 220. I got a new Barney 221. He got old one 222. I'n (‘didn't’) see that one, cause that one is very good 116 223. I got a different Barney 224. It's a boat 225. I can fall 226. Jesse can do it 227. I wanna play some games 228. This a new game? (‘Is this a new game?’) 229. We see clown at...umm... (‘We saw a clown at...’) 230. I see clown (= ‘saw a clown’) at a post office 231. Them have a party, and clown give me a balloon (‘They had a party and the clown gave me a balloon’) 232. He give a plane balloon (‘He gave me a balloon in the form of an airplane) 233. A funny one 234. I wanna play a stove (‘I want to play with a/the stove’) 235. I like it, cause, cause, I wanna play (reply to ‘Why do you like that stove?’) 236. I never saw one of these stove 237. Me making hot dogs 238. Her can cook something 239. Can cook at...somewhere 240. I don't know where her can cook 241. Daddy got train (Interviewer replies ‘Daddy got a train?’) 242. Me daddy (‘My daddy’) 243. I don’t know what he saying (Other child said something unintelligible) 244. That my brother (‘That’s my brother’) 245. I got a train (‘I’ve got a train’) 246. This is gonna be hot dog 247. This is gonna be coffee (Interviewer then asks ‘Do you like coffee?’) 248. I don't, I like tea (Interviewer then asks: ‘Do you like hot tea?’) 249. I like warm tea 250. I have tea at boy scout (= ‘at the boy scouts’') 251. You lost one of these 252. But we got two more 253. You take a cup and drink like this 254. You pour on here (Interviewer then asks ‘Do you have some ketchup?’) 255. How about pepper? (interviewer then says ‘I like pepper’) 256. That not pepper (‘That’s not pepper’) 257. I put this and this (Interviewer then says ‘Pepper makes me sneeze’) 258. It don't make me (‘It doesn’t make me (sneeze)’) 259. Peter laughed you (‘Peter laughed at you’) 260. Who's that? (hearing voice on the intercom. Interviewer replies ‘A teacher’) 261. You know her? (Interviewer replies ‘Yeah’) 262. Who? 263. Where Giovanni one? (‘Where’s Giovanni’s one?’) 264. Where Giovanni sticker? (‘Where’s Giovanni’s sticker?’) 265. I remember Recording 6: 17/3/94 age 4;5.23 266. That because is shamrock today (reply to ‘Why is everyone wearing green today?’) 267. Know what? Me teacher make cake (‘My teacher made a cake’) 268. Her make it (= ‘She made it’) for Ms Peggy a long time ago (interviewer then asks ‘Who's Ms. Peggy?’) 269. That's my speech teacher, a speech one (Interviewer then says ‘I thought Mrs. Holly was your speech teacher?’) 270. Me know, but my...me get two cause... 117 271. Me got Ms. Peggy speech teacher (‘I’ve got Ms Peggy as my speech teacher’) 272. We got a lotta fish for everyone [pointing to toys] 273. And then, you could get lots fish in there 274. It's got eye (‘It’s got an eye’) 275. It's a seagull 276. Know what? Me sister name Dawn (‘My sister’s name is Dawn’) 277. Her give me dad a lobster, a two lobster (‘She gave my dad a lobster, a pair of lobsters’) 278. Me mom put in here, cook them (‘My mum put them in here to cook them’) 279. Forgot to take them eyes out (‘She forgot to take their eyes out’) 280. And then, it give it to mom (‘And then ?he gave it to Mum’) 281. He say, put it down (‘She said Put it down’) 282. And then her say, ahhh! (‘And then she said Ahhh’) 283. And then her put on the floor, and we scare her (‘And then she put it on the floor and we scared her’) 284. Her say, ahh it's moving (‘She said Ahh, it’s moving) 285. And then, them cook them up (‘And then they cooked them up’) 286. And then it scared mom, so we gonna put him to trouble 287. And then he be trouble (‘And then he’ll be in trouble’. Interviewer then asks ‘Did you eat the lobster?’) 288. No, you can't eat eyes 289. Only you can eat skin (‘You can only eat the skin’) 290. And me dad eat it (‘And my dad ate it’) 291. Daddy cook it (‘Daddy cooked it’) 292. Hey, how do ... to pick them up? (referring to toys) 293. How do you do this? 294. Why he don't have a nose? 295. Me remember...ah I remember this 296. I remember that thing 297. Two lobsters 298. I know, he wanned242 to go and drop it 299. Lobsters don't go there 300. He jumped out 301. He bit me 302. Her eating a cookie (‘She was eating a cookie’ – describing a picture) 303. Then, her drink some water (‘Then she drank some water’) 304. Water make a cookie all gone (‘The water made the cookie melt’) 305. Lobster to eat for lunch 306. Maybe some lobster pinch him (‘Maybe some lobster pinched him’) 307. Lobsters live in an ocean (Interviewer then says ‘I think an ant bit him’) 308. You could have chicken pox (Interviewer then asks ‘Did you ever get bitten by an ant?’) 309. Me no, me grandma (= ‘my grandma’) did long time ago from a snake 310. Me remember her house snake 311. Her have a snake in the sink (‘She had a snake in the sink’. Interviewer then asks ‘In the sink?’) 312. No, amm, next to a xx 313. Then grandma get biten (= ‘got bitten’) by a snake 314. Then her got hurt (‘Then she got hurt’) 315. Then, me and xxx drop a xxx, then it hurt me 316. He try to eat me up (‘He tried to eat me up’) 317. How he gonna eat me up? 318. He grabbing a lollipop [describing a picture] 319. Me remember at school...ahm... 242 The t of want is dropped in colloquial American English in such forms, so that corresponding to Standard English wanted we find colloquial wanned. This can be treated as a regular (but contracted) past form of want. 118 320. What's I talking about? (‘What was I talking about?’) 321. Long time ago, I go camp (= ‘went camping’) and hiking at the same time 322. Then, I eating food 323. I say, and I eat at hiking 324. And then at hiking, I xxx a picnic, so we eat 325. But a bee eating it (‘A bee was eating it/ate it’) 326. Then a bee eat a little bit my food (‘A bee ate a little bit of my food’) 327. Then me said, oh! 328. Then me take it xxx (‘Then I took it xxx’) 329. Then me go camping (‘Then I went camping’) 330. Me eat all our food (‘I ate all our food’) Recording 7: 29/3/94 age 4;6.3 331. I mean this much (reply to ‘I don't want that many people in my room!’) 332. Not that again 333. We making books (‘We are making books’) 334. But, I got another one 335. My another one is lost 336. Easter eggs 337. Me mommy show me to make Easter eggs (‘My mummy showed me how to...’) 338. Now I do all by myself (‘Now I do them all by myself’. Interviewer then asks ‘How do you make them?’) 339. I forgot 340. Only he mom can teach him make it good (‘Only his mum can teach him to make it properly’) 341. That mean is already cook (‘That means it’s already cooked’) 342. No, you don't give one 343. You hafta take it with a mitten 344. You hafta take it with a little holder thing 345. With a egg thing 346. My dad make eggs, but mushy eggs (‘My dad makes eggs...’) 347. Me mom don't use paint brush (‘My mum doesn’t use a paint brush’) 348. Hers use with a green thing (‘She uses a green thing’) 349. Her use with a green cutter thing (‘She uses a green cutter thing’) 350. We just give to Easter Bunny 351. He can eat it 352. He hafta 353. Me mom hold in him hands (‘My mum holds it in her hands’) 354. Very careful so you can't drop it 355. We take one at a time 356. He put in a box with lots different and jelly bean (‘He puts the egg in a box with lots of different things and jelly beans’) 357. Then he bring it (‘Then he brings it’) 358. Then mom and kids find easter eggs 359. Then, I grab my one 360. Mom say, no, after lunch (‘Mom says ‘No, after lunch’) 361. Then, I eat it after lunch 362. I need ten stickers 363. I'm gonna be so proud Recording 8: 7/4/94 age 4;6.12 364. I know her (Interviewer then says ‘I see you got a hair cut’) 365. I got my hair from barber 119 366. But them cut my hair real tiny (‘But they cut my hair really short’) 367. Who first? 368. Me or him? 369. We got some new pictures (Interviewer then asks ‘Why do you think she needs the camera?’) 370. Her need the camera to put in a locker 371. I know these ones 372. It look like a lobster (‘It looks like a lobster’) 373. Them both have pinchers (‘They both have pincers’) 374. Why them both have pinchers? (‘Why do they both have pincers?’) 375. Both got legs 376. He...him go first 377. He taking a lollipop 378. He gonna bite you 379. He cut me 380. This is a good one