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LANGUAGE AND COGNITIVE PROCESSES, 2004, 19 (2), 225–271 Rules or schemas? Evidence from Polish Ewa Da˛browska Department of English Language and Linguistics, University of Sheffield, Sheffield, UK At least three factors—regularity, type frequency, and phonological heterogeneity—have been claimed to be implicated in determining the likelihood that a particular inflection will be applied to new stems. The role of these factors in determining Polish speakers’ productivity with genitive and dative inflections was investigated using nonce word production tasks and spontaneous child language data. Both children and adults freely generalised genitive masculine inflections, which are irregular but apply to large classes of phonologically heterogeneous nouns. However, speakers were only weakly productive with genitive neuter and dative neuter inflections, in spite of the fact that they are almost completely regular. This is attributed to the fact that the neuter class is relatively small, and that most nouns are clustered in a few densely populated phonological neighbourhoods. Thus, type frequency and phonological heterogeneity appear to be much better predictors of productivity than regularity. These findings are discussed in the context of single and dual mechanism approaches to morphological productivity. Perhaps the most fascinating of our linguistic capacities is the ability to produce forms we have never heard before. The last five decades have seen Correspondence should be addressed to Ewa Da˛browska, Department of English Language and Linguistics, University of Sheffield, Sheffield S10 2TN, UK. E-mail: [email protected]. This study was supported in part by British Academy grant RB 100556; much of the research was conducted while the author was visiting the Max Planck Institute for Evolutionary Anthropology in Leipzig. I would like to thank Magdalena Smoczyńska for generously providing me with a coded version of the Kraków corpus; Wojcich Kubiński, Ola Kubińska, Agata Kochańska, Anna Tymińska and Beata Williamson for their help in collecting the adult data; and Caroline Rowland, Marcin Szczerbiński, and two anonymous reviewers for very helpful comments on an earlier draft of the paper. Part of the material discussed here was presented at the Second International Conference on Construction Grammar (Helsinki, September 2002) and the Second International Conference of the Slavic Cognitive Linguistics Association (Turku, September 2002); the developmental data is discussed more fully in Da˛browska (2001). c 2004 Psychology Press Ltd http://www.tandf.co.uk/journals/pp/01690965.html DOI: 10.1080/01690960344000170 226 DA ˛ BROWSKA a formidable amount of research on the mental mechanisms which make this possible. In recent years, much of this research has focused on one particular aspect of linguistic creativity which is relatively easy to study— namely, morphological productivity, or the ability to produce inflected forms such as the plural of a noun or the past tense of a verb. There are two main approaches to explaining morphological productivity. According to one view, the human ability to supply the inflected forms of new words relies on a single mental mechanism. The best-known variant of this approach is associated with connectionist models such as those described by Elman et al. (1996), Plunkett and Marchman (1993), Rumelhart and McClelland (1986), and many others. Connectionist models consist of networks of interconnected ‘units’ loosely corresponding to neurons in the human brain. The strength of the connections between the units changes as the result of ‘experience’ (e.g., exposure to pairs of basic and derived forms of a number of lexemes). Such models are very good at extracting patterns implicit in the input and can generalise them to novel inputs; and according to proponents of this approach the process by means of which they accomplish this resembles human generalisation in some important respects. Another single-mechanism approach was developed by cognitive linguists and sometimes goes under the name of ‘schema theory’ (Bybee, 1995; Langacker, 1991, 2000; see also Taylor, 2002). The central premise of this approach is that people store large numbers of exemplars of complex units, and that similar exemplars have partially overlapping representations. Generalisations emerge as similarities inherent in exemplars are reinforced through repeated use. This results in the extraction of schemas of varying degrees of generality. For example, a schema which might be represented by the formula PAST/C(C)O:t captures the commonality between past tense forms such as bought, brought, caught, fought, and thought (they all refer to past events or states; they all consist of one or more consonants followed by the vowel [O:] followed by [t]), while PAST/ Verb-D captures the properties shared by all regular past tense forms (they refer to past events and the corresponding phonological form ends in an alveolar stop). The original function of schemas is to capture redundancies in the lexicon; however, once they become well-established, they can be used to inflect novel words. Like connectionism, schema theory maintains that generalisations emerge as a by-product of the way information is stored in long-term memory. Furthermore, both approaches emphasise the role of local similarities and of type frequency. The main difference is that schema theory (especially the version developed by Langacker) postulates more elaborate representations, and hence can account for a wider range of phenomena—though at the price of being less explicit about the actual RULES OR SCHEMAS? EVIDENCE FROM POLISH 227 details of acquisition and processing. However, the two approaches are broadly compatible, and in fact, connectionism may be regarded as a method of modelling some aspects of schema theory (Bybee, 1995: 428; Langacker, 1990). The subsequent discussion, therefore, will be couched in schema theory terms, although the points that will be made also apply to most connectionist models. The alternative position, which has been referred to as the dual mechanism theory or the hybrid model (Clahsen, 1999; Clahsen, Rothweiler, Woest, & Marcus, 1992; Marcus et al. 1992, 1995; Pinker, 1998, 1999) maintains that the memory-based system can explain only some aspects of linguistic productivity—specifically, the generalisation of irregular patterns such as those shared by strong verbs in English. To account for the full range of human abilities, however, we must postulate an additional, qualitatively different mechanism: symbolic rules. Symbolic rules concatenate a variable standing for a stem with an affix: for example, the English past tense rule adds the -ed ending to a verb stem to produce regular past tense forms such as played and kissed, and the plural rule adds -s to noun stems, resulting in composite forms such as cats and dogs. Unlike the memory system, symbolic rules are not constrained by phonological or semantic similarity. Because of this property, the regular inflection applies as a default whenever memory cannot be accessed. Thus, when confronted with nonce words in the course of a psycholinguistic experiment, English speakers usually use the regular inflection: asked to supply the past tense of snarf or the plural of wug, they almost invariably respond with snarfed and wugs (Prasada & Pinker, 1993). Outside the laboratory, they do exactly the same with other words for which they do not have stored entries, viz. newly coined words, recent borrowings, and low frequency words. Speakers also fall back on the default system when the memory trace is too weak or temporarily inaccessible. This situation arises most often in immature language users, since strong memory representations take time to build up; the result is regularisation errors such as comed, bringed, childs. Children also occasionally overgeneralise irregular patterns, producing past tense forms such as bat for bit (on analogy with sat) or truck for tricked (on analogy with drunk); such errors, however, are extremely rare (Xu & Pinker, 1995). Finally, the regular inflection is used with a variety of noncanonical forms such as onomatopoeic words, acronyms, and truncations, as well as with headless words, where information stored with an irregular root cannot be passed on to the derived form. The various circumstances in which memory cannot be accessed and hence the default inflection must apply are summarised in Table 1. It is worth noting that the circumstances are quite heterogeneous, and some are rather unusual. The fact that the dual mechanism theory gives a principled 228 DA ˛ BROWSKA TABLE 1 Circumstances in which memory is not accessed and the regular inflection is applied (adapted from Marcus et al., 1995) Circumstance Examples Nonce words krilged, wugs Overgeneralisation errors bringed, catched Low-frequency words stinted, eked Unusual-sounding words ploamphed, krilged Words with irregular homophones lied (cf. lay) hanged (cf. hung) Words which rhyme with irregular words blinked (cf. thought), glowed (cf. knew) Onomatopoeic words dinged, peeped The word is mentioned rather than used I checked the article for sexist writing and found three mans on page 1. Proper names the Childs (cf. children), the Manns (cf. men) Borrowings latkes, cappucinos Truncations synched, mans ‘manuals’ Acronyms PACs, OXes Derivation from different category: (a) denominal verbs (b) deadjectival verbs (c) nominalisations spitted ‘put on a spit’ righted ‘returned to an upright position’ ifs, ands, buts Derivation via different category: (a) via noun (verb ! noun ! verb) (b) via verb (noun ! verb ! noun) costed ‘calculated the costs’ wolfs ‘instances of wolfing’ Derivation via name Mickey Mouses, Renault Elfs Bahuvrihi (exocentric) compounds sabre-tooths, low-lifes Nominalised phrases bag-a-leafs, shear-a-sheeps explanation for why the regular inflection applies in all of them is a strong argument in its favour. There is also a fair amount of psycho- and neurolinguistic evidence suggesting that different mental mechanisms are involved in processing regular and irregular inflections. First, the two systems are sometimes differentially affected in language impairment. Individuals suffering from anomic aphasia and Alzheimer’s disease perform relatively well on regular verbs, but have problems with irregulars. Conversely, in agrammatics, Parkinson’s patients, and children with Specific Language Impairment, the regular system is disrupted, while the retrieval of irregular forms appears RULES OR SCHEMAS? EVIDENCE FROM POLISH 229 to be relatively unaffected (Marslen-Wilson & Tyler, 1997, 1998; Ullman et al., 1997b). Secondly, Jaeger, Lockwood, Kemmerer, Van Valin, and Murphy (1996) and Ullman, Bergida, and O’Craven (1997a) found that different areas of the brain were activated during the processing of regular and irregular past tense inflections, although these findings have been challenged by Seidenberg & Hoeffner (1998). Last but not least, it has been argued that performance on irregular verbs is highly sensitive to frequency and similarity to other irregulars, while regulars do not show such effects (Pinker & Prince, 1992; Ullman, 1999), although again, other studies report frequency and phonological neighbourhood effects for both regulars and irregulars (Alegre & Gordon, 1999; Marchman, 1997; Orsolini & Marslen-Wilson, 1997; Ramscar, 2002). As will be clear from the foregoing discussion, most of the evidence for the dual mechanism theory has come from studies of the English past tense. This raises a problem, since the regular and irregular past tense inflections differ in several respects: that is to say, regularity is confounded with other factors which may contribute to the observed differences. First, English regular and irregular verbs differ in frequency. Irregular verbs have very high token frequency: about 85% of past tense forms occurring in casual conversation are irregular (Marcus et al., 1992: 75). Regular verbs, in contrast, have a high type frequency: of the thousand most frequent verbs in English, 86% are regular (Pinker, 1999: 217). It is not difficult to see that high token frequency favours rote-learning: it is easy to memorise a frequently occurring form. High type frequency, in contrast, facilitates schema extraction: it is easier to notice a pattern shared by a large number of verbs than one which is shared by only a few. Second, English regular and irregular verbs invoke different morphological mechanisms to mark tense. The past tense of regular verbs is formed by suffixation (e.g., walk þ -ed), and the resulting form is easily segmentable into a component that specifies the type of process (walk) and a component that marks tense (-ed). Most irregular verbs, in contrast, require vowel changes (ring - rang, catch - caught, bite - bit, etc.)—a process which is less transparent, and therefore probably more difficult to generalise. Third, the various irregular patterns in English apply to clusters of phonologically similar verbs (e.g., ring-rang, sing-sang, spring-sprang), while the regular inflection is phonologically unrestricted. Although this is by no means untypical, it is certainly not invariably the case: some regular inflections (e.g., the ‘conjugations’ in Romance languages) are restricted to subsets of stems defined in phonological terms, and, conversely, irregular inflections may apply to phonologically open-ended classes (e.g., the Polish genitive masculine inflection, to be discussed below). Thus, English speakers’ reluctance to generalise irregular patterns to novel verbs may 230 DA ˛ BROWSKA be simply a consequence of the fact that they have very narrow domains of application. Because of these confounds, the English past tense is clearly not a good testing ground for theories of morphological productivity. The English plural inflection and the German past participle, which have also been extensively studied in connection with the single versus dual mechanism debate, are unsuitable for similar reasons. More recent studies which claim to provide support for the dual mechanism theory have focused on morphological subsystems in which regular and irregular inflections are better matched on other properties, such as person and tense marking in Spanish (Clahsen, Aveledo & Roca, 2002) and the Hebrew plural (Berent, Pinker & Shimron, 1999). In both of these subsystems, regular and irregular inflections apply to classes of comparable heterogeneity and rely on the same mechanism (inflectional suffixes). However, the frequency confound remains. Ninety per cent of masculine nouns in Hebrew (the class studied by Berent et al.) take the regular inflection; thus, regular forms outnumber the irregulars 9:1. The odds against irregular Spanish verbs are even higher. While the total number of irregular verbs is similar to the number of verbs in the smaller regular classes (in fact, it is slightly higher), the irregulars do not instantiate a single pattern but rather a collection of patterns—that is to say, different verbs are irregular in different ways. This means that any one irregular pattern applies to a much smaller number of verbs than any of the regular patterns. For example, the irregular first person singular past marker -e applies to just 30 verbs, while the corresponding regular endings (first conjugation -é and second/third conjugation -ı́) apply to about 10 000 and 1400 verbs respectively.1 Another morphological subsystem which has received a great deal of attention in the context of the single versus dual mechanism debate is the German plural. German has five plural affixes, -en, -e, -s, -er, and -Ø, three of which (-er, -e, and -Ø) sometimes require umlauting of the stem vowel. However, one of these endings, -s, appears to have properties which distinguish it from the other four. It is used with surnames, borrowings, headless words, words which are mentioned rather than used, etc.—that is to say, in many of circumstances associated with the regular past tense and plural in English. Furthermore, it is frequently overgeneralised by children, and applied to nonce words in psycholinguistic experiments. 1 Some irregular stem changes apply to slightly larger classes of verbs. However, in this case, there is yet another confound, namely phonological transparency: Forms with irregular stems are less transparent than forms with regular stems. Clahsen et al. acknowledge this (p. 617), and regard the children’s failure to generalise the irregular affixes rather than irregular stems as their strongest argument. RULES OR SCHEMAS? EVIDENCE FROM POLISH 231 These properties lead some researchers (Clahsen, 1999; Clahsen et al., 1992; Marcus et al., 1995) to conclude that -s is the default plural marker in German. It is not difficult to see that the German plural is a much better test case for the dual mechanism theory than the morphological subsystems considered so far. It is free from the confounds that beset the English past tense, since two of the irregular affixes (-en and -e) are also used with a wide variety of stems. What is more, the -s plural is relatively infrequent: in fact, it applies to only about 4–10% of the noun vocabulary. The fact that speakers freely generalise an infrequent affix undermines a central claim of single mechanism theories, namely, that type frequency is the most important determinant of productivity. Thus, the data presented by Marcus et al. (1995) and Clahsen et al. (1992) appear to provide particularly compelling evidence for symbolic rules of the kind postulated by the dual mechanism theory. However, the evidence for the claim that the -s affix is the default plural in German is far from clear-cut. As noted by a number of language acquisition researchers, German-speaking children overgeneralise all the plural markers, not just -s (Behrens, 2001, submitted; Bittner & Köpcke, 2000; Köpcke, 1998; Szagun, 2001), and the marker which is generalised most often is -en, the most frequent affix, not -s. Clahsen et al. acknowledge this, and propose that some children misidentify -en as the default.2 They point out that overgeneralisation errors with both -en and -s are ‘‘an order of magnitude’’ more frequent than errors involving the other affixes (Clahsen et al., 1992: 247–248). However, this is only true if one uses their method of calculating overgeneralisation rates, which involves dividing the number of errors with a particular affix by the number of all uses of that affix. If the error rates in their data are recalculated using the conventional method (as the ratio of errors to the number of opportunities for making error, i.e. the number of correct uses with other affixes), the differences disappear (see Da˛browska, 2001). There are also problems with the nonce word data. Although participants in the Marcus et al. (1995) study indeed preferred the -s plural, it appears that their stimuli were biased towards this ending. As pointed out by Behrens (submitted), a high proportion of the nonce words 2 Marcus et al. (1995) claim to have found some independent evidence for this. They observe that the children they studied sometimes left out the -en ending in compounds. Since irregular endings can occur inside compounds while regular endings normally do not (cf. micecatcher and *rats-catcher), the fact that children leave out -en in compounds, they argue, confirms that they have misidentified it as the regular ending. However, there are some serious problems with this argument (see Da˛browska, 2001). 232 DA ˛ BROWSKA used in the study were monosyllabic nouns ending in a plosive, and such nouns tend to take the -s plural. Other researchers, who used more varied stimuli, have found that participants had no particular preference for -s, and that their responses depended on the gender and the phonological properties of the stem: for example, they tended to choose -en with feminine nouns ending in -ung and masculine nouns ending in schwa, -e with masculine nouns ending in -ling, and -s with nouns ending in a full vowel (Köpcke, 1988; see also Gawlitzek-Maiwald, 1994). Finally, although it is true that -s is strongly associated with many of the default circumstances, it is by no means the only plural ending which occurs in them. Bahuvrihi compounds, for example, take whichever ending is required by the rightmost element (e.g., Schreihäls-e ‘bawlers’ (literally ‘scream-throats’), Großmäul-er ‘bigmouths’), and most rare words take endings other than -s (this is a matter of arithmetical necessity, since -s applies to only a small part of the noun vocabulary). Other exceptions include borrowings (only about 50% of which take -s), many nouns derived from other categories (e.g., nominalised verbs such as Modenschau-en ‘fashion shows’, Käuf-e ‘purchases’), some nominalised phrases (e.g., Tunichtgut-e ‘ne’er-do-wells’, Vergissmeinicht-e ‘forget-me-nots’), and, occasionally, abbreviations (e.g., LPG-en alongside LPG-s: Wegener, 1994: 269) and names (thus we have Emil-e, Anton-e, Beate-n alongside Emil-s, Anton-s, Beate-s). To summarise: The dual mechanism theory offers a convincing account of English speakers’ knowledge of past tense and plural inflections. Both of these have a single ‘default’ ending which applies in all the circumstances listed in Table 1; and there is strong evidence for various dissociations between regular and irregular inflections. However, it is not clear whether conclusions about English past-tense morphology can be generalised to other morphological systems, and to linguistic productivity in general. This is because the idiosyncratic properties of the English system of marking past tense exaggerate the differences between regular and irregular verbs, and make what could be quantitative differences appear qualitative. The same is true of most other morphological subsystems which have been used as testing grounds for the theory. The German data do offer partial support for the dual mechanism theory, in that it shows that even relatively infrequent affixes can be freely generalised to new words; but the results are far from conclusive. Clearly, what is needed are data from other languages. In this paper, I present the results of four studies designed to investigate Polish speakers’ productivity with the case inflections of their language—specifically, their ability to supply the genitive and dative inflections. These two inflections have been chosen because they make it possible to unconfound regularity from type frequency and phonological heterogeneity. The genitive RULES OR SCHEMAS? EVIDENCE FROM POLISH 233 masculine inflection is highly irregular and, it will be argued, lacks a ‘default’, while the corresponding feminine and neuter inflections are quite regular. Since the genitive masculine and feminine inflections apply to relatively large and phonologically heterogeneous classes of nouns, and all are signalled by affixes, the genitive case will allow us to examine the effects of regularity per se, and determine whether regular inflections are indeed more productive in the psychological sense. Study 1 will compare adult native speakers’ ability to inflect novel words of different genders in an experimental setting; and study 2 will analyse the use and non-use of the genitive inflections in a corpus of spontaneous child speech, with a view to determining whether there is a developmental advantage for regular inflections. The third study examines adults’ ability to supply the dative inflection with nonce words. Dative inflections for all three genders can be regarded as ‘regular’; however, they apply to classes which vary in size and phonological neighbourhood structure, thus making it possible to determine the degree to which class size and structure affect generalisability. The last study is a simple elicitation task with real words, conducted in order to confirm that the descriptions of the dative neuter ending given in published grammars of Polish are an accurate reflection of native speaker knowledge. I will also provide, for both the genitive and the dative, a linguistic analysis of the distribution of case endings in the default circumstances listed in Table 1, based principally on information provided in published grammars and dictionaries. This will make it possible to determine whether they are indeed uniquely associated with regular inflections. THE GENITIVE The genitive inflection The Polish case marking system is complex and fairly irregular. There are seven cases, each with two to four different endings (Table 2). The single TABLE 2 The Polish case marking system (the singular endings) Case Feminine Masculine Neuter Nominative Genitive Dative Accusative Instrumental Locative Vocative -a (-Ø, -i) -i/-y -‘e,a -i/-y -e˛ (-Ø) -a˛ -‘e,a -i/-y -o, -u, -i/-y, (-Ø) -Ø (-a, -o) -a, -u (-i/-y) -owi (-u, -‘e, -i/-y) -Ø, -a (-e˛, -o) -em (-a˛) -‘e,a -u (-i/-y) -‘e,a -u, (-o) -o, -e, -e˛ -a -u -o, -e, -e˛ -em -‘e,a -u -o, -e, -e˛ a The symbol ‘ indicates that the preceding consonant is palatalised. 234 DA ˛ BROWSKA most important factor determining the choice of ending is gender (which for most nouns can be reliably predicted from the phonological form of the nominative), with additional criteria becoming relevant when there is more than one marker for a particular gender. To complicate matters, some nouns, including all deadjectival nouns and most surnames, decline like adjectives—that is to say, require a completely different set of endings, which also depend on gender; some nouns, including many borrowings and foreign proper names, do not decline at all; and many nouns require stem changes as well as affixes. Most stem changes are quite regular, but some are restricted to small lexically specified classes or to individual lexemes. As can be seen from Table 2, the genitive case is signalled by one of three endings: -i/-y (considered variants of the same ending),3 -a, and -u. The -i/-y ending is characteristic for feminine nouns, and -a for neuters and animate masculine nouns; inanimate masculine nouns take either -a or -u, depending on the noun. There are no strict rules determining the distribution of genitive endings with inanimate masculine nouns, although there are certain tendencies (Bodnarowska, 1962; Kottum, 1981; Westfal, 1956). Some of these are semantic: for example, mass nouns, collective nouns, abstract nouns, and nouns referring to large objects and locations usually take -u, while nouns which designate tools, makes of cars, names of the months, body-part terms, and units of measurement generally take -a. Others are morphological: some derivational affixes (e.g., -acz, -arz, ek) are associated with -a, and some (e.g., -unek, -ot) ‘‘prefer’’ -u. And some are phonological: for instance, nouns that end in a palatalised consonant usually take -a, while nouns that end in -m or certain consonant clusters prefer -u. However, these criteria are not very reliable. There are many exceptions, and they are often contradictory: for example, a noun can be both abstract and end in a palatalised consonant; in some such cases, the phonological criterion wins, while in others it is the semantics. It is clear, then, that there is no single default ending which, unless blocked, applies freely to all nouns, although one could say that feminine and neuter nouns do have a default, namely, -i/-y and -a respectively. However, there remains a problem of the masculine declension with its 3 The endings -i and -y are in complementary distribution (i.e., the substitution of the wrong ending results in a phonotactically illegal sequence). Because of this, some linguists (e.g., Nagórko, 1998) consider them allophones of the same phoneme. This conclusion, however, depends on assumptions about the phonemic status of preceding consonants which are not shared by all linguists. RULES OR SCHEMAS? EVIDENCE FROM POLISH 235 two endings, both of which apply to open-ended classes of nouns. Since -a is the more frequent ending, it is traditionally regarded as the ‘regular’ one. However, according to the dual mechanism theory, regularity in the psychological sense (i.e., default status) does not depend on frequency, so in order to determine which, if any, of the two endings is regular, we must consider other criteria. As explained earlier, an important claim of the dual mechanism theory is that regular inflections must apply in the default circumstances discussed in the introductory section. Thus, we can use this set of circumstances as diagnostic contexts for identifying the default. If only one of the two endings can occur in these circumstances, we can conclude that that ending is regular in the technical sense of the theory; and if they allow neither ending, we would have to conclude that both endings are irregular. Before we proceed with the test, we must note that three of the circumstances enumerated in Marcus et al. (1995) are either not applicable to our data or do not allow us to distinguish regular and irregular forms. The former includes onomatopoeic words, since renditions of sound are always neuter, and the latter homophones and rhymes, which designate symmetrical relations, and hence do not allow us to determine which member of the pair takes the regular ending (for every -a noun that has a homophone that takes -u, there is a -u noun that has a homophone that takes -a; likewise, for every -a noun that rhymes with a -u noun there is a -u noun that rhymes with an -a noun). Also excluded from Table 3 are the first two circumstances listed in Table 1 (novel words and overgeneralisation errors), which will be discussed in the following two sections. The distribution of genitive masculine endings in the remaining 10 circumstances is summarised, with relevant examples, in Table 3. Bahuvrihi compounds and nominalised phrases are treated jointly because they are difficult to distinguish in Polish. As we can see from Table 3, most of the relevant default circumstances allow both endings; which ending is actually used depends on the lexical properties of the noun. Furthermore, some circumstances either allow or require other endings (-Ø or the adjectival -ego). Thus, neither of the two endings has a privileged status vis-à-vis the other one. Since they cannot both be regular (by definition, the default cannot depend on lexical properties of the stem), we must conclude that they are both irregular. This in turn implies that irregular inflections can be used in default circumstances, thus undermining one of the central claims of the dual mechanism theory. I now turn to a discussion of the psycholinguistic evidence. I begin with a report on adult performance in a nonce-word production task; this will be followed by a discussion of the acquisition of the genitive marking. TABLE 3 Genitive masculine endings in default circumstances Circumstance Required ending Examples (all forms given in the genitive) Low-frequency words -a -u szańc-a ‘bulwark’, tygl-a ‘crucible’ cze˛stokoł-u ‘palisade’, puchar-u ‘goblet’ Unusual-sounding words -Ø swahili, attaché, Delacroix Words mentioned rather than used -a, -u, or form in Nie moge˛ znaleźć tego drugiego ‘‘autorowi’’/ ‘‘autor-a’’/‘‘rasizm-u’’. ‘I can’t find the which the word was originally used second (occurrence of the word) ‘author (DAT)’/‘author (GEN)’/‘racism (GEN)’. Proper names -ego -a Tarski-ego, Chomski-ego Darwin-a, Bach-a Borrowings -Ø -u sometimes -a guru, boa, kamikadze, dingo fonem-u, pub-u, Wehrmacht-u drink-a, jeep-a, pikador-a Truncations -a sometimes -u merc-a ‘Mercedes’, spec-a ‘specialist’ sam-u ‘supermarket’ (from sklep samoobsługowy) Acronyms -Ø PCK (Polski Czerwony Krzyz_ ‘Polish Red Cross’) PAN-u (Polska Akademia Nauk ‘Polish Academy of Sciences’) -u Derivation from a different category: usually -a (a) affixation (b) backforation usually -u (c) nominalised adjectives -ego zszywacz-a ‘stapler’ (from zszywać ‘to stitch together’), lizak-a ‘lollipop’ (from lizać ‘to lick’) zbior-u ‘collection’ (from zbierać ‘to collect’), wykład-u ‘lecture’ (from wykładać ‘to lecture’) chor-ego ‘ill person’ (from chory ‘ill’), uczon-ego ‘scholar’ (from uczony ‘learned’) Derivation via a different -a category -u utleniacz-a ‘oxidant’ (from tlen ‘oxygen’ via utleniać ‘oxidize’) dodruk-u ‘additional print run’ (from dodrukować ‘print additional copies’ from drukować ‘to print’ from druk ‘print (n.)’ Derivation via name -a -u (ekranizacja) Hamlet-a/Króla Lir-a Tajfun-u/Wiśniowego Sad-u ‘(film version of) Hamlet/King Lear/Typhoon/The Cherry Orchard’ Bahuvrihi compounds and nominalised phrases -a łamistrajk-a ‘scab’ (lit. ‘break-strike’; cf. strajk-u ‘strike’), ka˛tomierza ‘protractor’ (lit. ‘angle-measure’) trójze˛b-u ‘trident’ (‘three-tooth’, cf. ze˛b-a ‘tooth’), długopis-u ‘ball-point pen’ (lit. ‘long-write’) -u 236 RULES OR SCHEMAS? EVIDENCE FROM POLISH 237 STUDY 1: ADULT PRODUCTIVITY WITH GENITIVE ENDINGS Ever since Berko’s (1958) classic study, the ability to inflect nonce words in an experimental setting has been regarded as the gold standard of productivity, and according to Marcus and Pinker, nonce words are one of the linguistic contexts in which the regular inflection applies. The following study, therefore, sets out to determine whether adults are productive with the masculine endings at all, and, if so, whether they are less productive than with the regular endings. The second objective is to determine whether Polish speakers are sensitive to the semantic and phonological factors affecting the choice of masculine ending. As explained earlier, there is a strong tendency for nouns designating small easily manipulable objects to take -a and for nouns designating substances to take -u; and some stem-final consonants or consonant clusters tend to be associated with one or the other of the two endings. Since, according to the dual mechanism theory, only irregular inflections are constrained by semantic and phonological factors, speakers’ sensitivity to such factors would confirm the irregular status of the masculine inflections. Method Participants. The participants were 60 native speakers of Polish (24 males and 36 females), aged from 17 to 70 years (mean 42 years), mostly of middle class background. All spoke standard Polish. Materials. Three lists of nonce words were compiled, each comprising 14 forms (see Appendix A). Each list contained eight masculine, four feminine and two neuter items. (Since the genitive ending for neuter nouns, -a, is identical to one of the masculine endings, the number of neuter items was intentionally kept small in order to minimise priming effects.) All the words had gender-typical offsets: -a for feminines, -o or -e for neuters, and a consonant for masculines. Of the masculine words, four ended in a consonant or consonant cluster which is strongly associated with -a ([˙], [Æ], [ts], [rs]) and four, with a consonant or consonant cluster strongly associated with -u ([m], [d], [st]; since there are only three consonant clusters strongly associated with -u, there were two nonce words ending in [m]). A consonant or consonant cluster was assumed to be ‘strongly associated’ with a particular ending if at least 80% of real Polish words with that offset took the same ending in the genitive; the relevant statistical data was extracted from Tokarski and Saloni (2002). The remaining 16 masculines ended in a variety of consonants distributed more 238 DA ˛ BROWSKA or less evenly over the entire phonological space. The lists contained words of one, two, and three syllables, in proportions intended to roughly reflect the statistical properties of the Polish lexicon. All forms had the phonotactic structure of real Polish words and were morphologically simple (that is to say, they did not contain any affixes other than a gender marker). Each nonce word was introduced in a context sentence in the nominative form (printed in bold face). The context sentence was followed by a test sentence with a blank in a grammatical context requiring the genitive. The nonce words were presented in three conditions: in a sentential context suggesting that the referent was an object, as in example (1) below, a substance, as in (2), or a place name, as in (3): (1) Jaka wielka anbasa! Nigdy nie widziałem takiej wielkiej _____. ‘What a large anbasa! I have never seen such a large ____.’ (2) Jez_ eli masa jest za ge˛sta, najlepsza jest patala. Po prostu dodaj troche˛ _____. ‘If the filling is too thick, patala is best. Just add some ____.’ (3) Szmargona lez_ y nad morzem. W przyszym roku pojedziemy do _____. ‘Szmargona lies near the sea. Next year we will go to ____’ As explained above, if speakers of Polish are sensitive to the semantic factors governing the choice of masculine inflection, they should prefer the -a ending in the object condition and the -u ending in the substance condition. Place names are equally likely to take -a and -u, so the final condition was introduced as a baseline for the other two. There were three versions of the test, with each of the three lists assigned to a different condition in each version. Thus, each participant encountered one-third of the words in the object condition, one-third in the place-name condition, and one-third in the substance condition. The test items were presented in three semi-random orders counterbalanced across participants. Procedure. Participants were given a printed copy of the questionnaire and were asked to read the sentences aloud, supplying the missing form. The test began with a single feminine practice item which, if necessary, was modelled for the participant. The responses to the test items were recorded by the experimenter. Participants were encouraged to answer quickly, ‘without thinking,’ and to give the first form that occurred to them, but when they did self-correct, only the final response was recorded. Each of the three versions was administered to one-third of the participants. RULES OR SCHEMAS? EVIDENCE FROM POLISH 239 TABLE 4 Response types by gender (%) Gender Expected responses (SD) Gender errors No change Other responses Masculine Feminine Neuter 93.5 92.4 65.0 (8.4) (10.7) (21.8) 2.6 1.5 16.1 3.9 5.0 18.3 0.0 1.1 0.6 Coding. Responses were coded as follows: expected ending (-a or -u for masculines, -i/-y for feminines, and -a for neuters); gender errors (e.g., feminine ending with a masculine or neuter noun); no change (i.e., nominative); other (no response; a different case or plural inflection). Results and discussion The descriptive statistics summarising performance according to gender are given in Table 4. The number of expected responses for masculine nouns was about the same as for feminine nouns—slightly higher, in fact. Performance on the neuter inflection, on the other hand, was considerably poorer than on the masculine (Wilcoxon signed ranks: z ¼ 6.3, N ¼ 60, p 5 .001, two-tailed) or feminine inflection (z ¼ 6.0, N ¼ 60, p 5 .001, two-tailed).4,5 A closer scrutiny of the responses to the masculine items reveals that both of the masculine endings were used productively, with -a being used 46.9% and -u 46.6% of the time. Furthermore, all nouns were sometimes inflected with -a and sometimes with -u, confirming that both endings are phonologically unrestricted. Graź, the word which got the most -a responses, was inflected with -u by 9 participants; and 14 participants used -a with kramost, the least ‘-u-friendly’ word. 4 As explained in the Method section, there were twice as many masculine items as feminines, and four times as many masculines as neuters, and hence the observed differences could be partially attributable to the fact that the masculine and feminine scores are more fine-grained than the neuter score. To check for this possibility, six neuter and six feminine words were randomly selected from each participants’ responses and a second analysis was carried out using the scores for these items. The results were almost identical to those reported in the main text. 5 In all the experiments reported in this paper, assumptions of normality were violated in at least one condition. Therefore, non-parametric tests have been used in all analyses. All reported significance levels have been corrected for multiple comparisons. 240 DA ˛ BROWSKA TABLE 5 Responses (%) to masculine nouns in the object, place and substance conditions Condition Mean SD Object Place Substance 77.3 43.8 19.8 24.1 32.9 23.7 On the other hand, it is clear that the respondents were sensitive to the phonological properties of the stem. Since the two endings are in complementary distribution, one can measure sensitivity to the contrast by differences in the number of responses with either ending. In the following discussion, I will use the number of -a responses. Participants supplied the -a ending with the four words ending in consonants strongly associated with -a 63.5% of the time (SD ¼ 23.7%); the corresponding figure for the words ending in consonants strongly associated with -u was 25.0% (SD ¼ 26.0%). The difference is highly significant (Wilcoxon signed ranks: z ¼ 6.0, N ¼ 60, p 5 .001, two-tailed). We now turn to participants’ sensitivity to the semantic factors governing the choice of masculine ending. The means and standard deviations for the object, place, and substance conditions are given in Table 5. The Friedman test revealed that the effect of semantics was highly significant (w2 ¼ 87.0, df ¼ 2, p 5 .001). Further analysis showed that there were significantly more -a responses in the object condition than in the place condition (Wilcoxon signed ranks test: z ¼ 6.0, p 5 .001, two-tailed) and significantly more -a responses in the place condition than in the substance condition (z ¼ 4.9, p 5 .001, two-tailed). We can conclude, then, that regularity in the technical sense of the dual mechanism theory is not a good predictor of productivity. Performance on the irregular masculine inflection was indistinguishable from performance on the regular feminine, while there was a very large difference in performance on the two regular inflections, with the neuter ending being supplied significantly less often than the feminine ending. (A possible explanation for this discrepancy will be proposed in the general discussion at the end of this section.) It is also clear that Polish speakers are sensitive to both the semantic and the phonological factors affecting the choice of masculine ending, confirming that the latter are irregular in the technical sense of the dual mechanism theory. STUDY 2: ACQUISITION OF THE GENITIVE We have seen that Polish adults freely generalise both of the masculine endings to novel nouns. Thus, the adult data are at odds with a central RULES OR SCHEMAS? EVIDENCE FROM POLISH 241 claim of the dual mechanism theory: namely, that irregular inflections are less productive (in the psychological sense) than regular inflections. In this section, we turn to child language data. The acquisition of the genitive inflection is potentially an even better testing ground for single and dual mechanism approaches, since they make different predictions not just about productivity, but also about the course of development and the type of errors that children make. According to schema theory, learners first extract low-level schemas by noting local similarities between stored exemplars; they may then generalise over these low-level schemas to form more abstract representations. One of the most important factors affecting generalisation is frequency, especially type frequency: inflections applying to large classes are learned earlier than inflections applying to smaller classes. Regularity as such has relatively little impact on ease or speed of acquisition, since both regulars and irregulars rely on the same mental mechanism. It may, however, affect error rates, which are likely to be higher in irregular systems, where there is more scope for error. The three genitive endings differ considerably in terms of frequency in the input (Table 6). The masculine -a and the feminine ending are both quite frequent (they apply to 36% and 43% respectively of the nouns in the language addressed to young children), while -u and the neuter -a apply to fairly small classes of nouns (9% and 12% respectively; note, however, that these proportions are different in the adult lexicon). Thus, if schema theory is correct, the two frequent endings (masculine -a and feminine -i/-y) should emerge at roughly the same time and develop at the same rate, while the neuter -a and the masculine -u, which apply to smaller classes of nouns, should be acquired somewhat later. One would also expect error rates to be highest on inanimate masculine nouns (since this is the most irregular part of the system), with -a, the more frequent ending, being overgeneralised more often than -u. TABLE 6 Frequency of the genitive singular endings Ending % nouns in inputa % nouns in adult lexiconb MASC -a MASC -u FEM NEUT 36 9 43 12 20 21 34 25 a Inka corpus (Smoczyńska, 1998). b Calculated from data given in Tokarski and Saloni (2002). 242 DA ˛ BROWSKA According to the dual mechanism theory, on the other hand, learners expect to find a default for every category and identify it by noting that a particular inflection applies in ‘one or two’ of the default circumstances listed in Table 1 (Marcus et al., 1995: 245); once they have identified the default inflection, they apply it across the board to all new words. Marcus et al. do not specify which ‘one or two’ of the default circumstances act as the triggering context, which makes it difficult to derive specific predictions regarding acquisition. However, whichever circumstance has this privileged status, Polish children will necessarily encounter some genitive ending in it, and hence could easily misconstrue it as the default and apply it to all new nouns. For example, if truncations were the telltale context, Polish children would conclude that -a is the default ending, since most truncations take -a; whereas if learners were to consider the endings used with acronyms, they would conclude that -u is the default, since acronyms, if they decline at all, take -u (Table 3). If children misconstrued one of the endings as the default, they should consistently overgeneralise that ending, and, because the system is quite irregular, we would expect overgeneralisation errors to occur quite frequently. However, it is also possible that children are able to identify systems without a default, and rely on associative memory alone when confronted with such a system. In this case, comparing the acquisition of the part of the system which lacks a default (the genitive singular of masculine nouns) with the acquisition of the parts of the system which do have one (the feminine and neuter inflections) would allow us to establish the degree to which being able to rely on symbolic rules helps the learner. If the dual mechanism theory is correct, we would expect to find clear differences between the acquisition of the masculine inflection on the one hand and the feminine and neuter inflections on the other—specifically, the masculine inflections should be acquired later than the feminine and neuter inflections, and the pattern of acquisition should be different (gradual increase in marking rates for masculines, sharp rise for feminines and neuters). We would also expect frequent overgeneralisation of the regular feminine and neuter endings. Interpreting this prediction is somewhat complicated by the fact that -a is the regular ending for neuters as well as an irregular ending for masculines; but it is clear that there should be more -i/-y errors than -u errors. Method The following analysis is based on spontaneous speech data from four of the ‘Kraków children’, Basia, Inka, Jaś, and Kasia (see Smoczyńska, 1998). The speech samples were collected in home settings, primarily by the RULES OR SCHEMAS? EVIDENCE FROM POLISH 243 mothers, as part of a project headed by Stefan Szuman, and digitised and tagged by Magdalena Smoczyńska. The data analysed here span the period from the emergence of the genitive until age 3;10 (Kasia) or 4;11 (the other three children). This part of the corpus comprises approximately 250 000 child words, including 8200 grammatical contexts which require the genitive, of which 7918 contain an explicitly marked genitive singular form. Since the corpus is coded for obligatory contexts, i.e., grammatical contexts which require a particular form, it is possible to automatically extract not just child utterances containing genitive forms, but also utterances in which the child should have used the genitive. This was accomplished using CLAN software (MacWhinney, 2000); all subsequent analyses were performed manually. All child forms were classified as either correct or incorrect; errors were further coded as zero marking (use of the citation form, i.e., the nominative, in a genitive context), overgeneralisations (use of an incorrect genitive ending), and other (use of the incorrect form of the stem, use of another case, or, very rarely, a stem without an ending). Results In what follows, I first summarise the error data, which address the question of whether or not the children can be said to have a default ending for masculine nouns (that is to say, whether there is a single ending which they apply consistently to all new nouns) and whether regular endings are always overgeneralised more frequently than irregular endings. I will then undertake an analysis of the rate and ‘shape’ of development of all genitive singular inflections in order to determine whether there is a developmental advantage for systems with a default. As we can see from the figures in Table 7, the children overgeneralised all three endings, although overgeneralisation rates were fairly low (0–2.2%). The feminine ending was the least likely to be overgeneralised; and -a was overgeneralised more frequently than -u. However, the difference in the frequency of -a and -u errors is small when compared with the vast differences in the frequency of regularisation and irregularisation errors in English.6 Moreover, it disappears when frequency of overgeneralisations is calculated in relative terms, i.e., as the ratio of the number of OG errors with a particular affix to the total number of uses of 6 According to Xu and Pinker (1995), English-speaking children irregularise past tense forms in only about 0.19% of the opportunities, while regularisation rates reported in the literature range from 4.2% (Marcus et al., 1995) to over 20% (Kuczaj, 1977). Thus, for the English past tense, regularisations are at least 20 times, and possibly as much as 110 times more frequent than irregularisations. 244 DA ˛ BROWSKA TABLE 7 Overgeneralisation errors Tokens correct -u AOG ratea Overgeneralisations -y/-i ROG rateb Child -a -a -u -y/-i -a -u -y/-i -a -u -y/-i Basia Inka Jaś Kasia Whole corpus 387 118 422 2 1050 424 1187 9 1137 429 1264 39 465 119 638 17 3039 1090 3511 67 1 2 10 15 28 0 3 1 2 6 0.4 0.6 2.3 2.2 1.4 0.1 0.1 0.4 1.3 0.4 0.0 0.2 0.1 0.3 0.1 0.5 0.9 3.3 3.5 2.2 0.8 0.5 2.3 11.2 2.5 0.0 0.4 0.1 0.3 0.2 Note. Data in rows 1–3 are from: Da˛browska, E. (2001). Learning a morphological system without a default: The Polish genitive. Journal of Child Language, 28, 566. a AOG rate (Absolute Overgeneralisation rate) ¼ OG errors as a percentage of the number of noun tokens requiring other affixes b ROG rate (Relative Overgeneralisation rate) ¼ OG errors as a percentage of the total number of tokens with a given affix. that affix, rather than as the ratio of the number of OG errors to the number of opportunities for making the errors, i.e., the number of noun tokens which require other endings. This suggests that the difference in the frequency of -a and -u errors is attributable to the differences in the frequency of the two affixes. It is also worth noting that most errors involved confusion of the two masculine endings; only 23% of overgeneralisations involved the use of gender-inappropriate endings. There is no evidence, then, that children treated any one ending as the default. Data on the age of emergence and acquisition of individual affixes is summarized in Table 8. The children began producing explicitly marked genitives between the ages of 16 and 18 months, and all four consistently supplied the genitive in obligatory contexts by 24 months. The earliest endings to be used productively, if we adopt the traditional criterion of use with at least three different types, are the feminine -i/-y and the masculine -a, with the former becoming productive somewhat earlier in two of the children; the masculine -u and the neuter ending reached this criterion a TABLE 8 Age of emergence and acquisition (in months) of the genitive endings First noun type Third noun type 90% correct Child FEM MASC-a MASC-u NEUT FEM MASC-a MASC-u NEUT FEM MASC-a MASC-u NEUT Basia Inka Jaś Kasia Mean 19 16 20 16 18 17 17 19 16 17 22 16 20 17 19 21 18 18 19 19 20 18 21 17 19 21 18 21 18 20 23 21 21 20 21 22 20 22 20 21 22 21 22 18 21 23 20 21 20 21 22 21 23 20 22 22 24 23 23 23 RULES OR SCHEMAS? EVIDENCE FROM POLISH 245 month or two later. This developmental sequence reflects the predictions of schema theory and is incompatible with those of the dual mechanism theory. However, this result could be a sampling artifact, since the more frequent endings are likely to have been recorded earlier even if all inflections appeared at the same time. If we adopt a more stringent criterion of productivity (marking rates of 90% or above) the picture is somewhat less clear. Three children (Inka, Jaś, and Kasia) acquired the feminine -i/-y and masculine -a earlier than the neuter ending; but only one child (Jaś) consistently supplied both of the frequent endings before -u. The fourth child, Basia, mastered all four endings virtually simultaneously. Thus, the order of acquisition is incompatible with the dual mechanism theory, since no child learned both the feminine and the neuter endings before the masculine, but it is only partially consistent with schema theory. Even with a sizeable corpus like the one studied here, there are not enough data to examine developmental changes in marking rates for individual affixes; and because the affixes apply to classes of different sizes, it is difficult to interpret growth rates expressed in terms of numbers of types. Therefore in the following discussion of the ‘shape’ of development, I will compare the acquisition of genitive marking in the two large classes, the masculines and the feminines. Figure 1 provides information about genitive marking rates according to gender, beginning with the month in which the child produced at least 10 noun tokens of both genders in genitive contexts (if there were fewer than 10 tokens for one or both genders in a particular month, the relevant numbers were collapsed with those for the following month). As we can see, in two of the children (Inka and Jaś) masculine marking rates were consistently higher than feminine marking rates, while Kasia had higher marking rates on feminine nouns. In Basia, feminine marking rates were higher in the beginning but then fell behind masculines. Thus, there is no evidence for any consistent differences in the rate or pattern of acquisition of the two inflections. Note that the marking rates shown in Figure 1 are quite high, even in the early months. This is because at the point at which these inflections appear, the children are producing predominantly single-word utterances, where it is difficult to identify obligatory contexts, and hence some zero marking errors are likely to have gone unnoticed. Because of this, the figures for the early months are probably overestimates of the children’s actual marking rates. Thus, it is more revealing to examine the pattern of growth by comparing the numbers of masculine and feminine noun types inflected for the genitive. Since the number of masculine and feminine nouns in the children’s productive vocabularies is approximately the same (44% and 41%, respectively), comparing the actual number of explicitly marked 246 Figure 1. Marking rates on masculine and feminine nouns. 247 Figure 2. Genitive noun types (cumulative). 248 DA ˛ BROWSKA types will give us a good measure of the productivity of the relevant inflections. Information about the cumulative numbers of masculine and feminine noun types which have been inflected for the genitive at least once is given in Figure 2. As we can see from the graphs, the curves for each child have very similar shapes: growth is fairly slow in the first two or three months after emergence and then gradually accelerates. What is more, the actual figures for masculine and feminine noun types are very similar at all stages of development. Again, we must conclude that the ‘shape’ of development is the same for both inflections. Discussion The data summarised above offer no support for either version of the dual mechanism theory of acquisition. The children clearly did not treat any one ending as the default for either masculine nouns or the noun class as a whole; and there is no evidence of any differences in either the rate or pattern of development of the regular feminines and irregular masculines: both inflections were acquired very early (before age 2) and, it would seem, in the same way. There is some evidence that endings which apply to larger classes were learned earlier, although the results are not completely clear-cut. The neuter inflection was learned last, as predicted by schema theory; but the masculine -u was sometimes mastered later and sometimes at the same time as the more frequent endings. It is clear, however, that type frequency is a much better predictor of the order of acquisition than regularity. We have also seen that the children overgeneralised all three endings, with -a and -u errors being considerably more frequent than errors involving the feminine ending. While the difference in frequency could be described as involving ‘‘an order of magnitude’’, it is in the opposite direction to that predicted by the dual mechanism theory: it is the irregular endings which are overgeneralised more often. This result is easily explained in terms of schema theory. The feminine ending applies to a well-defined class of nouns (namely, those which end in -a or -i in the nominative), and hence it is rarely over-extended to other classes; for the same reason, feminine nouns are rarely the target of overgeneralisation errors—that is to say, learners rarely add masculine or neuter endings to feminine nouns. On the other hand, the distribution of the masculine endings is largely unpredictable, leaving more scope for error. However, the errors tend to be confined to the masculine declension, since learners discover quite early on that feminine nouns take -i/-y and neuter nouns, -a. It is worth noting that of the two masculine endings, -a was overgeneralised more frequently than -u. This is readily explained as a RULES OR SCHEMAS? EVIDENCE FROM POLISH 249 type frequency effect, since -a is also considerably more frequent in the children’s correct productions (Table 8). Thus, overgeneralisation errors offer additional support for the claim that affixes which apply to larger classes are more likely to be generalised. GENERAL DISCUSSION OF THE GENITIVE DATA We have seen that the irregular masculine inflections apply in many of the ‘‘default’’ circumstances enumerated in Marcus et al. (1995), are freely generalisable to novel nouns, are acquired early, and follow the same course of development as the regular feminine endings. While this does not prove that symbolic rules do not exist, it does make them redundant, since associative memory appears to do the job equally well. Potentially even more problematic for the dual mechanism theory is the finding that even adults appear to be only partially productive with the regular neuter inflection. The respondents in the nonce word production task supplied the expected ending only 65% of the time with neuter nouns, and over 90% of the time with masculine and feminine nouns. This is a surprising finding, since the neuter inflection is not only almost completely regular, but also has a clearly defined domain of application—namely, neuter nouns, which nearly always end in -o, -e, or -e˛ in the nominative. So why are Polish speakers less productive with the neuter ending? The answer, I suggest, lies in the peculiar structure of the neuter class. The vast majority of neuter nouns belong to one of a few clusters defined by shared affixes or other morphological criteria. Many neuter nouns are formed by adding the suffix -nie or -cie to a verb root, e.g., pisanie ‘writing’, from the verb pisać ‘to write’, picie ‘drinking’, from pić ‘to drink’. Nominalisations with the affix -stwo and its variants -dztwo and -ctwo are also quite common, e.g., zwycie˛stwo ‘victory’ from zwycie˛z_ ać ‘to win’, społeczeństwo ‘society’ from społeczny ‘social’, kierownictwo ‘management’ from kierownik ‘manager’. Two other sizeable groups are diminutives in -ko (e.g., kółko ‘little circle’ from koło ‘circle’) and borrowings ending in -um such as muzeum ‘museum’ and archiwum ‘archives’. (Although -um is not a true affix, it is a morphologically relevant marker, in that words ending in -um do not inflect in the singular.) As we can see from the figures in Table 9, these five large groups comprise 61% of the most frequent neuter nouns, and 95% of neuter nouns listed in one large contemporary dictionary.7 There are also several 7 The 95% figure is probably an overestimate, as Janik-Płocińska et al. appear to have made the decision to list a -nie nominalisation for every verb in the dictionary, including prefixed verbs. This results in a very high proportion of -nie nouns, many of which are probably unattested. 250 DA ˛ BROWSKA TABLE 9 Proportion of neuter nouns in the five largest clusters Cluster High frequencya Mid frequencyb Dictionaryc -nie -cie -stwo/-dztwo/-ctwo -ko -um Total in clusters Rhymes with cluster Other 36 8 12 1 4 61 11 28 51 8 11 9 5 84 4 12 83 5 6 1 0 95 1 4 a 100 most frequent neuter nouns listed in Kurcz, Lewicki, Sambor, Szafran, and Worończak (1990) (mean frequency 228, range 50–462/500,000). b 100 least frequent neuter nouns listed in Kurcz et al. (1990) (frequency 4/500,000). c Sample of 159 words selected randomly from Janik-Płocińska, Sas, and Turczyn (2001). smaller groupings, and some of the remaining words rhyme with words containing one of the five affixes. The masculine and feminine classes, of course, also contain many morphologically complex words, but their proportion is much smaller (25–50% of the words listed in Janik-Płocińska et al., 2001). Thus, the composition of the neuter class is very different from that of the other two classes. A simple metaphor will help to visualise this difference. Psycholinguists sometimes talk about an abstract space defined by phonological properties with more or less densely populated ‘neighbourhoods’ (clusters of words sharing phonological features). Elaborating this metaphor, we can think of the neuter class as consisting of a few ‘cities’ (very densely populated neighbourhoods) separated by large stretches of almost empty ‘countryside’—somewhat like Australia. The masculine and feminine classes, on the other hand, are more like Europe or Japan: although there are a number of towns and cities, the surrounding countryside is also fairly densely populated. Given these differences in the phonological heterogeneity of the gender classes, schema theory offers a straightforward explanation for the observed differences in performance. According to the theory, learners’ initial generalisations are low-level patterns extracted by noting local similarities between specific items. Since words containing the same affix are similar at both the phonological and semantic level, generalisations over such words would seem particularly attractive to a mechanism which looked for local similarities. Thus, learners would initially extract schemas for action nominalisations ending in -nie, diminutives in -ko, and so on. At a later point in development, they would normally generalise over these local patterns, and thus arrive at more abstract schemas. This is probably RULES OR SCHEMAS? EVIDENCE FROM POLISH 251 what happens with the schemas for masculine and feminine nouns. However, in the neuter class, there may not be enough nouns outside the clusters, or not enough clusters, to force the learner to generalise further. This would result in an end state in which a speaker is able to inflect unfamiliar words belonging to one of the clusters, but not words which do fit any of the low-level schemas. Alternatively, a speaker may note that all neuter nouns take the same case ending, but fail to routinely apply this generalisation in production, preferring instead to rely on the more entrenched low-level schemas; this, of course, would lead to similar behavioural outcomes. In the following section, I report on an experiment designed to test this account by examining adult productivity with the dative inflection, which, for reasons to be explained below, is a better test case than the genitive. THE DATIVE The dative inflection The dative case has four distinct markers in the singular: -i/-y, -e, -owi, and -u. As in the genitive, the choice of ending is determined in the first instance by gender and, if there is more than one ending associated with a particular gender, by phonological and semantic properties of the noun. Feminine nouns take either -i (or its variant -y) or -e, depending on phonological features of the stem. The so-called ‘soft’ stems (those which end in [l] or a consonant with the feature [ þ palatal]) take -i; ‘hardened’ stems (ending either in an unpalatalised affricate or a post-alveolar fricative) take -y; and ‘hard’ stems (ending in any other consonant, i.e., a stop, an unpalatalised nasal, a labial, dental, or velar fricative, [w] or [r]) take -e. The latter ending triggers obligatory changes in the final consonant or consonants of the stem (see Tokarski, 2001 for details). The rules for masculine nouns are much simpler: the vast majority take -owi; about 20 take the irregular ending -u; and a somewhat larger group (all of which end in -a and refer to human males) take one of the feminine endings, with the choice again depending on the phonological properties of the final consonant of the stem. The neuter inflection is the simplest and most regular part of the system, with nearly all nouns taking the -u ending. The only exceptions are deadjectival nouns and indeclinable nouns; however, both of these exceptions are shared with the other genders—that is to say, all three genders contain nouns which decline like adjectives and nouns which do not decline at all. Two properties of the dative case make it a particularly suitable testing ground for the schema-theory account outlined above. First, it is the only 252 DA ˛ BROWSKA case in which the neuter ending is distinct from both the nominative and from the endings characteristic of other genders (if we disregard the 20 or so irregular masculines which take -u). This makes it possible to distinguish correct applications of the dative inflection, overgeneralisations of masculine endings, and zero marking errors. Secondly, using the dative case allows us to control for a possible confound, namely class size. As indicated earlier, the neuter class is relatively small, making up about 25% of the noun vocabulary. Since there is considerable evidence suggesting that type frequency is a major determinant of productivity, comparing neuters with one of the larger classes would yield ambiguous results: we would have no way of knowing whether any observed differences in productivity were due to class structure or simply class size. However, in the dative case, the feminine class is split up between two endings, and the number of nouns which take -e (18%) is roughly the same as the number of nouns which take the neuter ending. Before spelling out the predictions of the two theories, we must establish which of the four inflections are regular in the technical sense of the dual mechanism theory. The distribution of dative endings in default circumstances is summarised in Table 10. As we can see from the table, all four endings occur freely in most of the relevant default contexts, which suggests that all four are regular. This is not problematic for the theory, since the domain of application of each ending can be formulated in general terms (in contrast to the distribution of the genitive ending, which is lexically specific): -owi is used with masculine nouns, -u with neuters, -i/-y, with feminines whose stems end in a palatalised consonant, an affricate, a post-alveolar fricative, or [l], and -e with all other feminines. Nevertheless, the data in Table 10 considerably weaken three important claims of the dual mechanism theory. First, they show that the criteria given by Marcus et al. (1995) do not all pattern together crosslinguistically, since some circumstances require endings other than the usual regular inflections. Second, since the domain of application of the two feminine endings is defined partly in phonological terms, it follows that default rules may be sensitive to phonological properties of the stem. Third, the fact that unusual-sounding nouns do not inflect at all shows that none of the inflections can be construed as applying ‘across-the-board’ to a phonologically arbitrary class of stems. It is important to note that nouns that do not inflect in the dative do not inflect in other cases either, so no Polish case inflection is entirely insensitive to phonological properties of the noun (Orzechowska, 1998). It should be clear from the foregoing discussion that the dual mechanism theory and schema theory make rather different predictions with regard to Polish speakers’ ability to generate the dative form of unfamiliar words. The dual mechanism theory predicts good performance on all three 253 -owi -Ø Low-frequency words Unusual-sounding words -owi -emu -owi Word is mentioned rather than used Proper names Onomatopoeia Ending Circumstance Chomski-emu Darwin-owi (male names) Mówiełeś, z_ e majstersztyk to głupie słowo i nie powinienam go uz_ ywać w podaniu—ale dzie˛ki temu majstersztykowi dostałam prace˛! ‘You said that majstersztyk (‘masterpiece’) is a silly word and I shouldn’t use it in my application—but thanks to this majstersztyk I got the job!’ swahili, attaché, Delacroix szańc-owi ‘bulwark’ tygl-owi ‘crucible’ Examples Masculine -ej -Ø -e -i/-y -Ø -e -i/-y Ending Chomski-ej Darwin (female names) Mówiłeś, z_ e świta/kadź to głupie słowo i nie powinienam go uz_ ywać w podaniu—ale dzie˛ki tej świci-e/kadz-i dostałam prace˛! ‘You said that świta (‘retinue’)/kadź (‘vat’) is a silly word and I shouldn’t use it in my application—but thanks to this świta/kadź I got the job!’ gnu, tse-tse, pepsi, beri-beri świci-e ‘retinue’ kadz-i ‘vat’ Examples Feminine TABLE 10 Dative endings in the relevant default conditions etui, hobby, curry, interview Przysłuchiwałam sie˛ temu tik-tak, tik-tak, az_ zasne˛łam. ‘I listened to the tick-tock, tick-tock until I fell asleep.’ Mówiłeś, z_ e jarzmo to głupie słowo i nie powinienam go uz_ ywać w podaniu—ale dzie˛ki temu jarzm-u dostałam prace˛! ‘You said that jarzmo (‘yoke’) is a silly word and I shouldn’t use it in my application—but thanks to this jarzmo I got the job!’ -Ø -u jarzm-u ‘yoke’ kła˛cz-u ‘rhizome’ Examples -Ø -u Ending Neuter 254 -owi -Ø -owi -Ø Borrowings Truncations Acronyms uczon-ej ‘scholar’ (from uczona ‘learned’) -e -ej zbior-owi ‘collection’ (from zbierać ‘to collect’) uczon-emu ‘scholar’ (from uczony ‘learned’) -owi -emu (b) backformation (c) nominalised adjectives -i/-y walc-e ‘fight’ kamienic-y ‘tenement house’ harówi-e ‘hard work’ (from harówka ‘hard work’) zielen-i ‘(the colour) green’ (from zielony ‘green’) -e -i/-y zszywacz-owi ‘stapler’ OJA Organizacja Jedności Afrykańskiej ‘Organisation of African Unity’ fizi-e (from fizyka ‘physics’) biol-i (from biologia ‘biology’) kanaści-e ‘canasta’ pizz-y, fobi-i ‘phobia’ whisky, kakadu Examples -owi -Ø -i/-y spec-owi ‘specialist’ PCK (Polski Czerwony Krzyz_ ‘Polish Red Cross’) PAN-owi (Polska Akademia Nauk ‘Polish Academy of Sciences’) -e -e -i/-y -Ø Ending merc-owi ‘Mercedes’ pub-owi, drink-owi guru, boa, dingo Examples Feminine Derivation from a different category: (a) affixation -owi Ending Circumstance Masculine TABLE 10 (continued) -emu ciachu ‘biscuit, cookie’ (from ciast-ko) -u Wysoki-emu (place name; from wysokie ‘high’) pisani-u ‘writing’ (from pis- ‘write’) -u PLO (Polskie Linie Oceaniczne ‘Polish Ocean Lines’) kilo, zoo, euro -Ø -Ø lass-u ‘lasso’, curry, rodeo Examples -u -Ø Ending Neuter 255 Ending -owi -owi -owi Circumstance Derivation via different category Derivation via name Bahuvrihi compounds and nominalised phrases -e -i/-y ka˛tomierz-owi ‘protractor’ (lit. ‘angle-measure’) -e -i/-y -i/-y -e Ending łamistrajk-owi ‘scab’ (lit. ‘break-strike’) Hamlet-owi Lir-owi utleniacz-owi ‘oxidant’ (from tlen ‘oxygen’ via utleniać ‘oxidize’) Examples Masculine beztrosc-e ‘insouciance’ (from bez troski ‘without worry’) zagranic-y ‘foreign countries’ (from za granica˛ ‘over the border’) Karenini-e Barbarell-i słomianc-e ‘straw doormat’ (from słoma ‘straw’ via słomiany ‘straw [adj.]’) ludzkośc-i ‘humanity’ (from ludź- ‘people’ via ludzki ‘human’) Examples Feminine TABLE 10 (continued) poddasz-u ‘garret’ (from pod dachem ‘under the roof’) wodogłowi-u ‘hydrocephalus’ (from woda ‘water’ and głowa ‘head’) sznurowadł-u ‘shoe-lace’ (from sznur ‘rope’ via sznurować ‘to lace up’) -u -u Examples Ending Neuter 256 DA ˛ BROWSKA genders (since all three have default endings) and no differences between morphologically simple and derived words (since the same abstract rule would be applied in both cases). According to schema theory, on the other hand, we should expect good performance on morphologically simple masculines and feminines, since both of these classes contain large numbers of morphologically simple words scattered throughout phonological space, but not on neuters, because the lexical structure of the neuter class does not encourage generalisation. Speakers should, however, perform well on neuter nonce words which fall into the privileged neighbourhoods defined by the affixes discussed above. Furthermore, if productivity is related to type frequency, they should perform better on nonce words containing the highly productive -nie affix than on words with less productive affixes like -stwo or -ko. Finally, schema theory hypothesises that some generalisations that speakers extract may be too weak to support production. If so, performance should improve when the task involves merely recognising the correct form rather than producing it. STUDY 3: ADULT PRODUCTIVITY WITH DATIVE ENDINGS Method Participants. The participants were 92 undergraduates from two Polish universities studying for degrees in foreign languages. All spoke standard Polish as their first language. Materials. The participants were given a pen-and-paper test containing 48 nonce words, including 8 morphologically simple masculine nouns; 8 morphologically simple feminine nouns (all belonging to the class that takes -e); 8 morphologically simple neuter nouns; 8 neuter words with the diminutive suffix -ko; 8 neuter words with the nominalising suffix -nie; 8 fillers (4 masculine, 4 feminine). All the nonce words were phonotactically legal and had gender-typical endings; hence it was possible to predict gender from the phonological form of the nominative. A list of all the nonce words used in the experiment is given in Appendix B. Each test item consisted of a context sentence which introduced the nonce word (printed in bold face) in the nominative and gave a simple RULES OR SCHEMAS? EVIDENCE FROM POLISH 257 description of the referent, followed by a test sentence containing a blank in a grammatical context which required the dative—either the preposition dzie˛ki ‘thanks to’ or the verb przyjrzeć sie˛/przygla˛dać sie˛ ‘to look (carefully) at’. (4) Famagon to świetne lekarstwo na przezie˛bienie. Dzie˛ki _________ od razu sie˛ lepiej poczujesz. ‘Famagon is an excellent medicine for colds. Thanks to _________, you will feel better immediately.’ In addition to the definition and the test sentence, the 16 test items with morphologically complex nonce words also contained clues about morphological structure. In the case of diminutives, the relevant information was conveyed by an additional clause indicating that the -ko-suffixed word referred to a small exemplar of the type designated by the previously defined word: (5) Łuciero to przedmiot słuz_ a˛cy do pomiaru wilgotności, a łucierko to po prostu małe łuciero. Dzie˛ki _________ wiemy, kiedy trzeba wła˛czyć urza˛dzenia nawilz_ aja˛ce. ‘A łuciero is a device for measuring humidity, and a łucierko is simply a small łuciero. Thanks to a _________ we know when to turn on the humidifier.’ For action nominalisations, the clue about derivational structure was provided by introducing the base verb in the infinitive: . (6) Zrewienie jest trudne i wymaga duz_ ego dos´wiadczenia. Jez_ eli chcesz sie˛ nauczyć z_ rewić, najlepiej zapisz sie˛ na kurs. Osobiście wole˛ przygla ˛ dać sie˛ _________. . ‘Zrewing is difficult and requires considerable experience. If you . want to learn to zrew, you should sign up for a course. Personally I prefer watching _________.’ The neuter nouns were interspersed with feminine and masculine nouns (MNFN etc.). There were three versions of the questionnaire with three different orders, counterbalanced across participants. Procedure. The participants were randomly allocated to either a production or a forced-choice task. Those assigned to the production task were asked to write the nonce word in the blank in the second sentence. In the forced-choice task, participants were asked to pick out the correct form from an array of four: the stem with the masculine ending, the stem with the feminine ending, the stem with the neuter ending, and the nominative. 258 DA ˛ BROWSKA All participants were given an example containing a real word. The test took about 15 minutes to complete. Coding. Responses were coded as follows: expected ending (-owi for masculines, -e for feminines, -u for neuters); gender errors (e.g., a masculine or feminine ending with a neuter noun); no change (i.e., nominative); other (no response; a different case or plural inflection; -i responses for feminine nouns). If a respondent gave two answers, only the first one was recorded. Results Although the study investigated the effects of two factors, gender and morphological structure, the latter was varied only in neuter nouns. Therefore, for ease of exposition, the results of the manipulation of gender and morphological structure in the production task are reported separately. This will be followed by a comparison of performance on the production task and the forced-choice task. Production task: Morphologically simple words. Performance on morphologically simple masculine, feminine, and neuter words is summarised in Table 11. A Friedman test with number of responses with the expected ending as the dependent variable showed a significant effect of gender (w2 ¼ 74.3, df ¼ 2, p 5 .001). Further analysis revealed that, as predicted, performance on masculine nouns was significantly better than on neuter nouns (Wilcoxon signed ranks: z ¼ 5.6, N ¼ 46, p 5 .001, twotailed), and performance on feminine nouns was significantly better than on neuter nouns (z ¼ 5.9, p 5 .001, two-tailed). Surprisingly, performance TABLE 11 Performance on morphologically simple words in the production task (%) Gender Expected responses (SD) Wrong gender No change Other MASC FEM NEUT 89.1 97.6 46.7 (16.6) (6.2) (23.0) 9.5 1.9 41.0 1.1 0.0 9.8 0.3 0.5 2.4 RULES OR SCHEMAS? EVIDENCE FROM POLISH 259 on feminines was significantly better than on masculine nouns, although the effect was much smaller (z ¼ 3.3, p ¼ .003, two-tailed). It is worth noting that nearly all gender-inappropriate responses involved overgeneralisation of the masculine -owi ending (73 instances) or the feminine -e (118 instances); there were only two instances of -u overgeneralisations, accounting for just 1% of the gender errors. These results suggest that adult native speakers of Polish either have not formed a generalisation about neuter nouns, or else the generalisation is too weak to be reliably used in production. This conclusion is confirmed by a more detailed analysis of individual participants’ responses to neuter nouns, which turned out to be extremely inconsistent, with the same respondent sometimes using the neuter ending, sometimes the feminine ending, and sometimes leaving the noun uninflected. The mean number of different response types per participant was 3.3 in the neuter condition and 1.5 and 1.2 in the masculine and feminine conditions respectively. The difference is relatively large (Wilcoxon signed ranks test: z ¼ 5.7 for the masculine v. neuter condition and 5.9 for the feminine v. neuter conditions, N ¼ 46) and highly significant (p 5 .001). Production task: morphologically complex words. Another Friedman test comparing performance in the three neuter conditions revealed a significant effect of morphological type (w2 ¼ 67.1, df ¼ 2, p 5 .001). The Wilcoxon signed ranks test showed that performance in the nominalisation and the diminutive conditions was significantly better than in the simplex condition, although the difference was considerably larger in the former case (z ¼ 5.9, N ¼ 46, p 5 .001) than in the latter (z ¼ 2.4, N ¼ 46, p ¼ .04). The difference between the nominalisation and the diminutive condition was also highly significant (z ¼ 5.5, N ¼ 46, p 5 .001). The details of performance on morphologically complex words and the baseline simplex condition, converted into percentages, are given in Table 12. The mean number of different responses per participant was 2.2 for diminutives TABLE 12 Performance on simplex neuters, diminutives and nominalisations (%) Condition Expected (SD) Gender errors No change Other Simplex Diminutives Nominalisations 46.7 56.3 98.4 (23.0) (32.3) (6.8) 41.0 43.0 0.3 9.8 0.3 0.5 2.4 1.1 0.8 260 DA ˛ BROWSKA and 1.1 for nominalisations, both significantly lower than the corresponding figure in the simplex condition (3.3; p 5 .001). Forced choice task. Performance on the forced-choice task is summarised in Table 13. The Friedman test indicated that the number of times that participants used the expected (i.e., gender-appropriate) ending differed significantly between conditions (w2 ¼ 108.4, df ¼ 4, p 5 .001), and further analysis (Wilcoxon signed ranks) confirmed that the differences were in the predicted direction: that is to say, performance on simplex neuters was significantly worse than in all other conditions, and performance on diminutives was not as good as on -nie nominalisations (p 5 .001 for all comparisons). Thus, the forced-choice part of the study replicated the general results discussed above. We now turn to a comparison of performance on the forced-choice and production tasks. Note that it would be inappropriate to compare actual scores on the two tasks, since we would have no way of knowing whether any observed differences in performance were due to the fact that recognising a correctly inflected form is easier than producing it or to the fact that the forced-choice task is more structured—that is to say, there are only three ways to be wrong on the forced-choice task, whereas there are indefinitely many incorrect responses that one could give on the production task (e.g., one could supply a stem inflected for another case, or a plural ending, substitute a familiar word, etc.). To control for this, the scores from the production study were recalculated as a ratio of correct forms to the sum of correct forms, gender-inappropriate forms, and zero responses—that is to say, all responses classified as ‘other’ were excluded from the analysis. The results of the comparison are presented graphically in Figure 3. As we can see, changing the elicitation method made no difference in the simplex feminine and neuter nominalisation conditions (where participants performed at ceiling on both tasks) or in the simplex masculine condition. TABLE 13 Performance in the forced-choice task (%) Condition Expected (SD) Gender errors No change Simplex MASC Simplex FEM Simplex NEUT Diminutives Nominalisations 89.7 98.4 57.3 73.6 99.4 (15.0) (4.3) (27.8) (29.8) (2.6) 10.3 1.6 35.4 26.1 0.6 0.0 0.0 7.3 0.3 0.0 RULES OR SCHEMAS? EVIDENCE FROM POLISH 261 Figure 3. Expected responses (%) in production and forced choice tasks in the simplex masculine (MASC-Sx), simplex feminine (FEM-Sx), simplex neuter (NEUT-Sx), neuter diminutive (NEUT-ko), and neuter nominalisation (NEUT-nie) conditions. Performance on the forced-choice task was somewhat better in the simplex neuter condition, but the difference is not statistically significant (Mann– Whitney U ¼ 843.5, p ¼ .091). The only significant improvement occurred in the diminutive neuter condition (U ¼ 692.0, p ¼ .02). These results suggest that speakers indeed have more knowledge about neuter dative diminutives than they are able to demonstrate in the production task. On the other hand, there is no strong evidence for an overarching neuter dative schema, since the improvement in the simplex neuter condition was modest and not statistically significant. It is worth noting, however, that the findings reported above do not rule out the possibility that some speakers may have a fully abstract neuter schema. This is evident when we compare performance of the highest- and lowest-scoring participants in each group. Table 14 gives the mean scores for the two tasks by quartile. As we can see, the difference in performance TABLE 14 Performance on simplex neuters by quartile Percentile Production Forced choice Forced choice —production 76–100 51–75 26–50 1–25 77 60 40 17 93 70 46 23 16 10 6 6 262 DA ˛ BROWSKA on the production and forced choice task is greatest in the top quartile (where performance on the forced-choice task approaches ceiling), and smallest in the lowest quartile. Thus, the difference between the two conditions is not attributable simply to scores being uniformly higher in the force-choice task, but also to the fact that the highest-scoring participants performed particularly well on the latter task, which may be due to the availability of a general schema for neuters. STUDY 4: THE DATIVE INFLECTION WITH FAMILIAR NOUNS All the results discussed so far involved nonce word stimuli. Given the poor performance on morphologically simple neuters, the possibility arises that the -u ending may be a historical artifact of little relevance to speakers. Before we proceed with the discussion, therefore, it will be useful to rule out this possibility by showing that speakers do in fact reliably supply the neuter ending with ordinary words. Method Twenty adult native speakers of Polish were given a pen-and-paper test consisting of 24 sentences with blanks in grammatical contexts which required the dative case. Next to each blank was a noun in the nominative, which participants were instructed to use in the appropriate form. The test contained 12 morphologically simple neuter words and 12 fillers. Half of the neuter words were relatively frequent (mean lemma frequency 107 per 500,000, mean dative frequency 2 per 500,000) and half were relatively infrequent (estimated mean lemma frequency 3 per 500,000; estimated dative frequency less than 1 per 500,000; see Appendix C for further details). Results Respondents supplied the expected ending 99% of the time with highfrequency neuters and 89% with low-frequency neuters. The difference was statistically significant (Wilcoxon signed ranks: z ¼ 2.2, N ¼ 20, p ¼ .026, two-tailed). Thus, Polish speakers reliably supply the -u ending with familiar neuters, and perform slightly better on high-frequency nouns. GENERAL DISCUSSION OF THE DATIVE DATA We have seen that adult native speakers of Polish reliably supplied the expected ending with morphologically simple masculine and feminine nouns and neuter -nie nominalisations, but performed very poorly on simplex neuters, showing that they are not fully productive with the neuter RULES OR SCHEMAS? EVIDENCE FROM POLISH 263 ending.8 These differences in productivity are difficult to accommodate in the dual mechanism framework, since all three inflections are regular. They are, however, easily explained in the schema theory account. According to schema theory, learners initially extract low-level generalisations over clusters of similar words; more abstract generalisations are a later development. Because of the peculiar structure of the neuter class, with most words clustered in a few densely populated neighbourhoods, learners do not progress beyond low-level schemas. To explain all of the results, however, schema theory must also account for the fact that speakers were able to supply the expected ending with morphologically simple nonce words almost 50% of the time. Two distinct possibilities come to mind here. First, it is possible that speakers have a general schema as well as the low-level schemas mentioned above, but the former is too weak to be reliably used in production. Alternatively, speakers may only have local schemas, and rely on another, less reliable mechanism (such as analogy) to inflect stems that cannot be subsumed under local generalisations. The results reported here do not provide conclusive evidence that would enable us to choose between these hypotheses; and indeed, as indicated earlier, there may be individual differences in this regard: it is possible that some speakers do have a general schema in addition to local schemas, while others do not. It is also evident that speakers have very specific knowledge about the inflected forms of individual lexemes. Before learners can generalise, they need something to generalise over: in other words, they must memorise a number of exemplars of the relevant pattern. As pointed out by Langacker (1991), there is no reason to suppose that the memorised words which served as the basis for the generalisation are deleted from memory when the generalisation is extracted. In a similar vein, there is no reason to suppose that people stop memorising further exemplars after they have abstracted the schema: after all, the necessary memory mechanisms are still in place. Indeed, since it is easier to learn structured material, the availability of the schema should facilitate further rote-learning. This view is corroborated by the results of the real word study. As we have seen, 8 Performance on simplex neuters in the dative was even worse than in the genitive: respondents supplied the expected ending only 47% of the time, whereas in the genitive experiment, the corresponding figure was 65%. However, this may be attributable to the fact that the genitive neuter ending, -a, is identical to one of the masculine endings. Thus, some of the -a responses in the genitive experiment could have been overgeneralisations of the masculine ending. It is interesting to note in this connection that in the dative experiment respondents used the masculine ending with neuter nouns in 18% of the opportunities. If we assume that speakers are equally likely to overgeneralise the masculine ending in both cases and subtract 18% from the total number of -a responses to neuter nouns in the genitive experiment, we get 47% – the same figure as in the dative experiment. 264 DA ˛ BROWSKA performance on morphologically simple real words was much better than performance on nonce words; and performance on high-frequency words was better than performance on low frequency words. Both of these findings suggest that the inflected forms of many familiar words are retrieved from the lexicon as ready-made units. The picture that emerges, then, is that of a relatively loosely organised network in which word-specific representations co-exist with low-level schemas of varying degrees of entrenchment.9 By traditional linguistic standards, such a system is messy and redundant, which suggests that speakers’ mental grammars (unlike linguistic theories) are shaped by principles other than simplicity and elegance. It is worth noting in this connection that there is also some purely linguistic evidence suggesting that speakers normally rely on concrete schemas. As observed earlier, unusual-sounding borrowings like guru, gnu, and etui do not inflect—not just in the genitive and dative, but in all cases. This shows that none of the schemas that speakers normally use in production applies to a set of stems which is completely open phonologically. Other indeclinable borrowings suggest that the productive schemas are quite specific. For example, kamikadze and attaché also do not take any case endings, in spite of the fact that there are many Polish nouns ending in -e in the nominative. However, all the native words which end in -e are neuter, and kamikadze 9 Preference for low-level schemas may also explain the puzzling finding that respondents performed better on feminine nouns than on masculines. As explained earlier, the distribution of feminine endings in the dative case is determined by phonological factors: stems ending in [l] or a consonant with the feature [ þ palatal] take -i; stems ending in postalveolar fricatives or unpalatalised affricates take -y; and stems ending in stops, fricatives (except postalveolars), unpalatalised nasals, [w], or [r] take -e. Although the choice of ending is predictable from the final consonant of the stem, the sets of consonants associated with each ending do not form natural classes. Thus, the distribution of each ending must be defined in terms of fairly specific schemas: if the noun ends in a postalveolar fricative followed by -a, it takes -y in the dative, if it ends in -la it takes -i, and so on. The schemas for the -e ending may be even more specific, since it always triggers changes in the final consonant(s) of the stem: for example, nouns ending in -ka [ka] in the nominative end in -ce [tse] in the dative, nouns ending in -ła [wa] in the nominative end in -le [le] in the dative, nouns ending in -sna [sna] in the nominative end in -śnie [ Æe] in the dative, and so on (see Tokarski, 2001, p. 78). Dative marking on masculine nouns, on the other hand, is much simpler: they nearly always take the -owi ending, and, if there are stem changes, they are shared with other cases (that is to say, a given stem will have the same form in all oblique cases). What is more, the masculine ending applies to a large class, and there are proportionally fewer morphologically complex nouns. All this leads to the general schema becoming more entrenched, and could, paradoxically, result in more errors, if speakers are indeed more proficient with low-level schemas. If the above proposal is correct, then speakers’ knowledge about the dative feminine inflection would be embodied in a network of low-level schemas similar to that for the neuter inflection. The only difference would be that, because feminine nouns are distributed much more evenly throughout phonological space, the low-level schemas would cover more or less the whole ground. RULES OR SCHEMAS? EVIDENCE FROM POLISH 265 and attaché are assigned masculine gender because they prototypically refer to male beings; hence, none of the existing low-level schemas are applicable. Similarly, pepsi and beri-beri inherit feminine gender from the superordinate term, i.e., cola and choroba ‘illness’. In this case, there are a number of native feminine nouns ending in -i, but they all refer to women, and nearly all contain the suffix -yni. Consequently, these nouns, too, are judged to be too dissimilar from the established schema and are left uninflected. As a final example, consider the nouns nazi, pony, and husky, which are all masculine. While there are native masculine nouns that end in -i or -y, e.g., zbójnicki ‘a kind of folk dance’, uczony ‘scholar’, gajowy ‘forest ranger’, they are all transparently deadjectival (-cki, -ny, and -owy are affixes used to derive adjectives from nouns and verbs, so all three words involve derivation of a noun via an adjective). Thus again, these nouns cannot be subsumed under any local schema and are left uninflected. The results reported above offer strong support for the schema theory predictions about the role of local schemas in language processing. With regard to the role of frequency, the evidence is more mixed. There is evidence that frequency does play a role: in the real vocabulary, there are many more nominalisations with -nie than -ko diminutives (Table 9), and, as we have seen, performance on nonce nouns with -nie was much better than performance on diminutives. On the other hand, it is clear that frequency measured simply as the number of words which take a particular affix cannot be the whole story. First, the neuter -u applies to approximately the same number of nouns as the feminine -e—slightly more, in fact—and yet the feminine ending is freely generalised to nonce words while the neuter one is not. Second, speakers were more likely to supply the expected ending with feminine nouns than with masculines, in spite of the fact that the masculine ending -owi applies to more than twice as many nouns as -e. Finally, the type frequency of neuter nouns with the -nie suffix is necessarily lower than the type frequency of all neuter nouns, so frequency alone cannot explain the difference in performance in the nominalisation condition and the simplex condition. Our earlier conclusions about the importance of local generalisations may help to resolve this apparent paradox. If learners’ initial generalisations are local (i.e., if speakers initially generalise over phonologically similar clusters of words which may also share semantic properties), then what matters is the number of words in a particular cluster, not the overall frequency of the ending. Hence, it is legitimate to compare local generalisations over clusters of various sizes (e.g., -nie and -ko neuters), since the corresponding schemas are at the same level of abstraction; but it is probably inappropriate to appeal to type frequency when comparing local and global generalisations. If the latter are indeed more difficult to 266 DA ˛ BROWSKA extract, speakers need more experience before they reach the same level of proficiency. Furthermore, at the moment it is not clear how to count the nouns in clusters. If higher-level generalisations are generalisations over clusters, then what matters may be the number of clusters rather than the number of words in all the clusters. Generally speaking, it seems that some work in the single-mechanism framework (Marchman & Bates, 1994) overemphasises the role of frequency. Frequency is only one of the determinants of productivity, and phonological coherence is probably more important. CONCLUSION The dual mechanism theory proposed by Pinker, Marcus, and their colleagues offers a convincing account of the English past tense and plural inflection, where there are indeed strong dissociations between regular and irregular patterns. These, however, may be attributable to the adventitious properties of the English system of marking tense and number, which exaggerate the differences between regulars and irregulars. In order to evaluate the theory, therefore, it is necessary to consider data from other languages. As pointed out in the introductory section, the evidence provided by research on the German plural inflection and other crosslinguistic studies is far from conclusive. There is even less support for the theory in the Polish data. Contrary to a central claim of the theory, default circumstances do not pattern together in Polish, and irregular endings can occur in most of them. Furthermore, all inflections, both regular and irregular, appear to be sensitive to the phonological and/or semantic properties of the noun, since noncanonical nouns do not inflect. In acquisition, there is no evidence of any differences in either the rate or pattern of development of the regular genitive feminine inflection and the irregular masculine inflections (except that, contrary to the predictions of the dual mechanism theory, there are more overgeneralisation errors involving the latter). Most fatally, regularity is a poor predictor of productivity in adults. Polish adults are only weakly productive with the regular dative neuter inflection, but freely generalise the irregular masculine endings to novel nouns. It should be stressed that the results reported here are not necessarily incompatible with other ‘dual route’ models such as Caramazza, Laudanna, and Romani’s (1988) Augmented Addressed Morphology or Schreuder and Baayen’s (1995) race model. Like the theory put forward by Pinker and Marcus, these models state that there are two ways of producing a morphologically complex form: it can be either assembled by combining component morphemes or simply retrieved from memory. However, neither Caramazza et al. nor Schreuder and Baayen equate the RULES OR SCHEMAS? EVIDENCE FROM POLISH 267 two routes with regular and irregular morphology: they specifically allow the direct access route to be used with regularly inflected forms (particularly if they are high-frequency); and they do not necessarily rule out the possibility that the parsing/assembly route is used with irregulars (provided that they are productive and have a reasonably clear domain of application). Both of these theories are concerned with how information is represented in the mental lexicon, and the two ‘routes’ correspond to different ways of accessing stored information. This in sharp contrast to the approach advocated by Pinker, Marcus, and their colleagues, who propose an additional memory-independent mechanism—symbolic rules. The question that was the main focus of this study is whether this additional mechanism is necessary. Even the proponents of the dual mechanism theory acknowledge that the memory system for irregulars is productive. They argue, however, that it is productive only to a limited degree, so that symbolic rules are necessary in order to give a complete account of human ability to inflect words. The evidence reviewed here suggests that the memory system is powerful enough to explain all that needs to be explained. The fact that the genitive masculine inflections (which must be regarded as irregular, since their choice depends on lexical properties of the stem) are as productive and as easy to acquire as the feminine ending makes symbolic rules redundant: it seems that associative memory can do the job equally adequately. In other words, the same mental mechanism— schemas of varying degrees of generality—can account for speakers’ ability to supply the correct inflected form of familiar stems, whether regular or irregular, as well as their ability to inflect new words.10 Manuscript received November 2002 Revised manuscript received July 2003 10 It is also possible to interpret the similarities between regular and irregular processes reported here as evidence for the ubiquity of rules rather than memory-based schemas—in other words, one could maintain that it is ‘rules all the way down’ rather than ‘associative patterns all the way down’. Whether or not this conclusion is warranted depends on how one defines rules and schemas—in other words, it is a terminological issue rather than a substantive one. If a ‘rule’ is simply any generalisation that learners extract from the language they hear, then we can indeed say that all productive use involves the application of a rule. However, the term is usually used to refer to something rather more specific than this. Rules are often thought of as fully general (or, more precisely, formulated at the most general level compatible with the data), insensitive to frequency and phonological similarity effects, and independent from the memory system. This view of rules is incompatible with the evidence presented here, which suggests that (i) speakers extract patterns at different levels of generality, and appear to prefer low-level patterns; and (ii) the nature the generalisations that speakers extract is determined by type frequency and phonological heterogeneity of the class to which it applies. 268 DA ˛ BROWSKA REFERENCES Alegre, M., & Gordon, P. (1999). Frequency effects and the representational status of regular inflections. Journal of Memory and Language, 40, 41–61. Behrens, H. (2001). Learning multiple regularities: Evidence from overgeneralisation errors in the German plural. In A. H.-J. Do, L. Dominguez, & A. Johansen (Eds.), Proceedings of the 26th Annual Boston University Conference on Language Development (pp. 72–83). Somerville, MA: Cascadilla Press. Behrens, H. (submitted). How to learn a minority default: The acquisition of the German -s plural. Berent, I., Pinker, S., & Shimron, J. (1999). Default nominal inflection in Hebrew: evidence for mental variables. Cognition, 72, 1–44. Berko, J. (1958). The child’s learning of English morphology. Word, 14, 150–177. Bittner, D., & Köpcke, K.-M. (2000). Acquisition of the German plural markings: A case study in natural and cognitive morphology. In C. Schaner-Wolles, J.R. Rennison, & F. Neubarth (Eds.), Naturally! Linguistic Studies in Honour of Wolfgang Ulrich Dressler Presented on the Occasion of his 60th Birthday (pp. 45–58). Torino: Rosenberg & Sellier. Bodnarowska, J. (1962). Problematyka doboru końcówek -a/-u w dopełniaczu l.p. rzeczowników me˛skich. Je˛zyk Polski, 42, 29–49. Bybee, J.L. (1995). Regular morphology and the lexicon. Language and Cognitive Processes, 10, 425–455. Caramazza, A., Laudanna, A., & Romani, C. (1988). Lexical access and inflectional morphology. Cognition, 28, 297–332. Clahsen, H. (1999). Lexical entries and rules of language: A multidisciplinary study of German inflection. Behavioural and Brain Sciences, 22, 991–1060. Clahsen, H., Aveledo, F., & Roca, I. (2002). The development of regular and irregular verb inflection in Spanish child language. Journal of Child Language, 29, 591–622. Clahsen, H., Rothweiler, M., Woest, A., & Marcus, G.F. (1992). Regular and irregular inflection in the acquisition of German noun plurals. Cognition, 45, 225–255. Da˛browska, E. (2001). Learning a morphological system without a default: The Polish genitive. Journal of Child Language, 28, 545–574. Elman, J.L., Bates, E.A., Johnson, M.H., Karmiloff-Smith, A., Parisi, D., & Plunkett, K. (1996). Rethinking innateness: A connectionist perspective on development. Cambridge, MA: MIT Press. Gawlitzek-Maiwald, I. (1994). How do children cope with variation in the input? The case of German plurals and compounding. In R. Tracy & E. Lattey (Eds.), How tolerant is universal grammar? Essays on language variability and language variation (pp. 225–266). Tübingen: Niemeyer. Jaeger, J.J., Lockwood, A.H., Kemmerer, D.L., Van Valin, R.D., & Murphy, B.W. (1996). Positron emission tomographic study of regular and irregular verb morphology in English. Language, 72, 451–497. Janik-Płocińska, B., Sas, M., & Turczyn, R. (2001). Wielki słownik ortograficzno-fleksyjny. Warszawa: Horyzont. Köpcke, K.M. (1988). Schemas in German plural formation. Lingua, 74, 303–335. Köpcke, K.M. (1998). The acquisition of plural marking in English and German revisited: Schemata versus rules. Journal of Child Language, 25, 293–319. Kottum, S.E. (1981). The genitive singular form of masculine nouns in Polish. Scando-Slavica, 27, 179–186. Kuczaj, S.A. (1977). The acquisition of regular and irregular past tense forms. Journal of Verbal Learning and Verbal Behavior, 16, 589–600. RULES OR SCHEMAS? EVIDENCE FROM POLISH 269 Kurcz, I., Lewicki, A., Sambor, J., Szafran, K., & Worończak, J. (1990). Słownik frekwencyjny polszczyzny współczesnej. Kraków: Polska Akademia Nauk. Langacker, R.W. (1990). The rule controversy: A cognitive grammar perspective. Centre for Research in Language Newsletter (University of California, San Diego), 4(3), 4–15. Langacker, R.W. (1991). Concept, image and symbol: The cognitive basis of grammar. Berlin: Mouton de Gruyter. Langacker, R.W. (2000). A dynamic usage-based model. In M. Barlow & S. Kemmer (Eds.), Usage-based models of language (pp. 1–63). Stanford, CA: CSLI Publications. MacWhinney, B. (2000). The CHILDES Project. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Marchman, V.A. (1997). Children’s productivity in the English past tense: The role of frequency, phonology and neighbourhood structure. Cognitive Science, 21, 283–304. Marchman, V.A., & Bates, E. (1994). Continuity in lexical and morphological development: A test of the critical mass hypothesis. Journal of Child Language, 21, 339–366. Marcus, G.F., Brinkman, U., Clahsen, H., Wiese, R., & Pinker, S. (1995). German inflection: The exception that proves the rule. Cognitive Psychology, 29, 189–256. Marcus, G.F., Pinker, S., Ullman, M., Hollander, M., Rosen, T.J., & Xu, F. (1992). Overregularization in language acquisition. Monographs of the Society for Research in Child Development, 57, 1–180. Marslen-Wilson, W.D., & Tyler, L.K. (1997). Dissociating types of mental computation. Nature, 387, 592–594. Marslen-Wilson, W.D., & Tyler, L.K. (1998). Rules, representations, and the English past tense. Trends in Cognitive Science, 2, 428–435. Nagórko, A. (1998). Zarys gramatyki polskiej (ze słowotwórstwem). Warszawa: PWN. Orsolini, M., & Marslen-Wilson, W. (1997). Universals in morphological representation: Evidence from Italian. Language and Cognitive Processes, 12, 1–47. Orzechowska, A. (1998). Rzeczownik. In R. Grzegorczykowa, R. Laskowski, & H. Wróbel (Eds.), Gramatyka współczesnego je˛zyka polskiego. Morfologia (pp. 270–332). Warszawa: Wydawnictwo Naukowe PWN. Pinker, S. (1998). Words and rules. Lingua, 106, 219–242. Pinker, S. (1999). Words and rules: The ingredients of language. London: Weidenfeld and Nicolson. Pinker, S., & Prince, A. (1992). Regular and irregular morphology and the psychological status of rules of grammar. Berkeley Linguistics Society, 17, 230–251. Plunkett, K., & Marchman, V. (1993). From rote learning to system building: Acquiring verb morphology in children and connectionist nets. Cognition, 48, 21–69. Prasada, S., & Pinker, S. (1993). Generalisations of regular and irregular morphological patterns. Language and Cognitive Processes, 8, 1–56. Ramscar, M. (2002). The role of meaning in inflection: Why the past tense does not require a rule. Cognitive Psychology, 45, 45–94. Rumelhart, D.E., & McClelland, J.L. (1986). On learning the past tenses of English verbs. In D.E. Rumelhart & J.L. McClelland (Eds.), Parallel distributed processing: Explorations in the microstructure of cognition. Volume 2: Psychological and biological models (pp. 216– 271). Cambridge, MA: MIT Press. Schreuder, R., & Baayen, H. (1995). Modeling morphological processing. In L. B. Feldman (Ed.), Morphological aspects of language processing (pp. 131–154). Hillsdale, NJ: Lawrence Erlbaum Associates Inc. Seidenberg, M.S., & Hoeffner, J.H. (1998). Evaluating behavioural and neuroimaging data on past tense processing. Language, 74, 104–122. 270 DA ˛ BROWSKA Smoczyńska, M. (1998). Krakowskie dane je˛zykowe dzieci w systemie CHILDES. In M. Smoczyńska (Ed.), Studia z psychologii rozwojowej i psycholingwistyki (pp. 283–296). Kraków: Universitas. Szagun, G. (2001). Learning different regularities: the acquisition of noun plurals by Germanspeaking children. First Language, 21, 109–141. Taylor, J.R. (2002). Cognitive grammar. Oxford: Oxford University Press. Tokarski, J. (2001). Fleksja polska. Warszawa: PWN. Tokarski, J., & Saloni, Z. (2002). Schematyczny indeks a tergo polskich form wyrazowych. Warszawa: PWN. Ullman, M.T. (1999). Acceptability ratings of regular and irregular past tense forms: Evidence for a dual-system model of language from word frequency and phonological neighbourhood effects. Language and Cognitive Processes, 14, 47–67. Ullman, M., Bergida, R., & O’Craven, K.M. (1997a). Distinct fMRI activation patterns for regular and irregular past tense. NeuroImage, 5, S549. Ullman, M.T., Corkin, S., Coppola, M., Hickok, G., Growdon, J.H., Koroshetz, W.J., et al. (1997b). A neural dissociation within language: Evidence that the mental dictionary is part of declarative memory, and that grammatical rules are processed by the procedural system. Journal of Cognitive Neuroscience, 9, 2–27. Wegener, H. (1994). Variation in the acquisition of German plural morphology by second language learners. In R. Tracy & E. Lattey (Eds.), How tolerant is universal grammar? Essays on language variability and language variation (pp. 267–294). Tübingen: Niemeyer. Westfal, S. (1956). A study in Polish morphology. The genitive singular masculine. The Hague: Mouton. Xu, F., & Pinker, S. (1995). Weird past tense forms. Journal of Child Language, 22, 531–556. APPENDIX A Nonce words used in Study 1 Words labelled with (a) and (u) end in consonants or consonant clusters strongly associated with that ending. Gender List 1 List 2 List 3 Feminines szmargona kruma filinga nyra patala uka karada garbodzia anbasa glamisia śruna oronica Masculines grumb figoń (a) malirach ćwiarg ekrod (u) kramost (u) gamal piastorgaj oktom (u) czapic (a) purk flors (a) ścigor famagon grotocz galiro_z sor syragin supang progonys klum (u) graź (a) milaj bukarsz Neuters orocino somie folgo orowie glorko oposie RULES OR SCHEMAS? EVIDENCE FROM POLISH 271 APPENDIX B Nonce words used in Study 3 Masculine simplex Feminine simplex Neuter simplex Neuter diminutive Neuter gerund ekrod ścigor famagon syragin flors supang czapic ćwiarg anbasa patala filinga nyrda garyta kruma oronica śruna folgo orocino somie orowie klimo żulo świele mrosie murewko suremko grułko łucierko żurbko chruńko krucinko dziutko smuntowanie szawocenie rakszenie kloskowanie śrydzenie żrewienie prodoczenie opotuwianie APPENDIX C Words used in Study 4 The frequency information is based on Kurcz, Lewicki, Sambor, Szafran, and Worończak (1990), who list all words which occurred at least four times in their 500,000-word corpus of written Polish. Words with the entry ‘ 5 4’ in the lemma column were not listed and hence their exact frequency is unknown Frequency Word English translation Lemma frequency Dative frequency Low bydle˛ cygaro fiasko futro koryto piskle˛ Mean beast cigar fiasco fur trough chick 54 54 54 54 54 55 between 2.8 and 3.8 51 51 51 51 51 51 51 High prawo szcze˛ście zero słońce serce niebo Mean right, law luck zero sun heart sky, heaven 249 67 76 93 94 65 107 52 52 52 53 52 51 52