engleski

Verb overgeneralizations in morphologically rich languages: the role of frequency and class size of verbs

During language acquisition, children often overgeneralize transparent morphological patterns to irregular words (e.g., bring to bringed instead of brought in English). Overgeneralized forms reveal strategies children use when confronted with morphological complexity. Highly inflected languages exhibit features of language acquisition not entirely consistent with findings in less inflected languages (Dressler 2005), especially English, which is usually taken as a model to draw conclusions about this phenomenon. The Croatian conjugation system displays various degrees of complexity based on the number of inflectional morphemes and on an elaborate system of stem changes. For most verbs the infinitive stem and the simple present stem differ in phonological features (cf. šet-a-ti.INF ‘to walk’ and šeć-e-m.PRS.1SG ‘I walk’). During early language development, children are likely to use overgeneralized forms interchangeably with adult-like forms (e.g., plesati.INF 'to dance' > plesam / plešem.1SG 'I dance'). In the research on the acquisition of inflectional morphology, two main factors influencing the occurrence of overgeneralization can be identified – token frequency (how often a child is exposed to a particular verb form) and phonological neighbourhood density or class size (the number of verbs with phonologically similar word stems and inflection). Not many studies investigated the influence of these factors in morphologically rich languages, especially on the acquisition of verbal morphology (cf. Kirjavainen, Nikolaev & Kidd 2012 ; Engelmann et al. 2019). The aim of this study was to investigate the production of overgeneralized verb forms in Croatian-speaking children aged 2 ; 6 to 5 ; 11 using a questionnaire in which parents report children’s overgeneralizations. We hypothesized that parents will report overgeneralized forms in all verb classes, but that the frequency of overgeneralizations will depend on the features of the input, i.e. it will be predicted by the frequency of verbs (higher rate of overgeneralizations for infrequent verbs) and class size (higher rate of overgeneralizations for verbs with smaller class size). A total of 36 verbs were investigated. For each verb, two items were created: the 'adult-like' form and the overgeneralized form. The frequency of verbs was calculated from the longitudinal child language corpus (CDS, Kovačević, 2002) and corpus of written adult language (hrWaC, Ljubešić & Klubička 2014). The class size was calculated from the same sources in lemmas, tokens and tokens of selected types. Parents were asked to indicate how often their child produces a particular verb form using a 5-point Likert scale. Our results show overgeneralized forms in child language for all verbs included in the questionnaire. We found a negative relationship between the proportion of overgeneralized forms and the overall verb frequency in both CDS and hrWaC. Verbs with a lower frequency have a higher proportion of overgeneralized forms. We also found a negative relationship between the class size in tokens (CDS) and both the frequency of overgeneralized forms and the proportion of overgeneralized forms. The frequency of overgeneralized forms and the proportion of overgeneralized forms are lower in larger classes. Our results are consistent with previous studies (e.g. Engelmann et al. 2019). Preschool children still resort to mechanisms of overgeneralizations in highly inflected language.

acquisition of morphology ; overgeneralizations ; verbs ; verb classes

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