Download A MaxEnt model of L2 Zapotec learners` overgeneralization of

A MaxEnt model of L2 Zapotec learners’ overgeneralization of glottal stop coda
Like infant learners, second language learners often overgeneralize forms or rules to
contexts where they do not apply in the target language (Ortega, 2009). Research on this topic
has most often dealt with the regularization of irregular verbal morphology, though there is some
evidence that learners overgeneralize phonological patterns as well (e.g., Face, 2006). What is
not clear is what drives this overgeneralization. Ortega (2009) states that overgeneralization in
second language acquisition “can apparently be random” (p. 117). In this paper, I argue that
overgeneralization of glottal stop codas by child second language learners of Zapotec can be
predicted by the probabilistic characteristics of the input they receive. This is modeled using
Hayes’ (2009) MaxEnt Grammar Tool.
Data for this study come from 10 hours of audio and video recordings of an after-school
language revitalization program with native Spanish-speaking children who were learning
Zapotec as a second language for the first time. Data were transcribed with the aid of a native
speaker of Zapotec to create a mini-corpus of instructor and learner data. Preliminary qualitative
analyses revealed that many students inserted glottal stop codas into words that do not contain a
glottal stop coda in targetlike speech. In the Zapotec variety examined for this study (Sierra
Juarez Zapotec) the glottal stop consonant is restricted to coda position but allowable in all
possible coda positions (Foreman, 2006), cf. ettseʔe ‘fill’, iyuʔni ‘wrinkle’, gattaʔ ‘lie down’.
According to the Dictionary of Sierra Juarez Zapotec (Nellis & Nellis, 1983), approximately
37% of words in the lexicon exhibit a glottal stop coda. Token frequency scores based on the
instructor speech in the video data were entered into the model along with the set of relevant
markedness and faithfulness constraints given in (1).
(1)
MAX: Retain all input segments in the output
DEP: Retain only input segments in the output
NOCODA: Codas are prohibited
*#ʔ: No onset glottal stop
*ʔ.C: No glottal stop before a following consonant
*ʔ.V: No glottal stop before a following vowel
*ʔ#C: No word-final glottal stop before a following consonant
*ʔ#V: No word-final glottal stop before a following vowel
*ʔ##: No utterance-final glottal stop
Two models were run using the MaxEnt Grammar Tool. The first model aimed to create
a targetlike ranking of the constraints in (1) and therefore constraint violations were entered
based on the instructor’s production data. The second model aimed to show the learners’
constraint ranking, and therefore constraint violations were entered based on the learners’
production data. The results indicated that overgeneralization of glottal stop codas was
predictable from learners’ input. The results also showed that unlike the target grammar, the
learner grammar weighted *ʔ## lower than all other markedness constraints, suggesting perhaps
that the glottal stop is more salient to learners utterance-finally than in other coda positions.
Interestingly, learners did not violate the *#ʔ constraint, which is undominated in the target
grammar. Overall, these results suggest that modeling overgeneralization using probabilistic
learning frameworks can provide evidence that overgeneralization is not random but driven by
probabilistic distributions in the input. This finding also provides general support for
probabilistic approaches to second language phonology acquisition.
References
Face, T. (2009). Intervocalic rhotic pronunciation by adult learners of Spanish as a second
language. Selected Proceedings of the 7th Conference on the Acquisition of Spanish and
Portuguese as First and Second Languages, Carol A. Klee and Timothy L. Face (Eds.),
47-58. Somerville, MA: Cascadilla Proceedings Project.
Foreman, J. (2006). The morphosyntax of subjects in Macuilitianguis Zapotec. University of
California Los Angeles, Ph.D. Dissertation.
Hayes, B. (2009). MaxEnt Grammar Tool. Retrieved from
http://www.linguistics.ucla.edu/people/hayes/MaxentGrammarTool/ on October 15,
2014.
Nellis, N., and Nellis, J.G. (1983). Diccionario Zapoteco de Juarez. Mexico City: SIL.
Ortega, L. (2014). Understanding second language acquisition. London: Hodder Education.