Morphosyntactic development of typically- and atypically-developing Bangla-speaking children.
Thesis DisciplineSpeech and Language Sciences
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
Aims: Verb morphology, arguably, is identified as an area of exceptional challenge for the language development of both young typically-developing children, and children with language difficulties (Leonard, 2014a; Rice & Wexler, 2001). The developmental patterns of verb acquisition are found to be strongly governed by the typological properties of the ambient language; often language errors found in fusional languages (e.g. English and German) are significantly different from those found in agglutinative languages (e.g. Turkish and Tamil) (cf. Phillips, 2010). Therefore, the purpose of the study was to explore the developmental trends in the acquisition of verb morphology in Bangla, a language with agglutinative features. The first objective was to examine the morphosyntactic development of typically-developing (TD) Bangla-speaking children with regard to three verb forms, namely the Present Simple, the Present Progressive and the Past Progressive. A second objective was to examine the development of the three verb forms among a group of children with language impairment (LI).
Rationale: Since Bangla is spoken by a large population, the acquisition data of Bangla represents a significant number of people, and the findings from the acquisition studies, when considered for intervention purposes, serve a considerably large population. Also, given that the normative data of language acquisition is unavailable for Bangla which leads to the absence of a language-specific assessment and intervention for LI children, the present study is expected to have importance for Bangla-speaking contexts.
Method: Before the main study commenced, a pilot study was conducted with 19 Bangla-speaking TD children aged between two and four (years) in order to explore the developmental characteristics of the verb forms and to evaluate the research instruments identified for the actual study. The main study included 70 TD children between 1;11 and 4;3 years who were recruited from six daycare centres of Dhaka, Bangladesh. The children participated in three elicitation tasks, each to elicit one verb form, and a 20-minute play session that yielded a spontaneous language sample from each child. The researcher scored children’s performances on the three tasks, and transcribed the language samples using transcription software (Systematic Analysis of Language Transcripts). The elicitation tasks were used to determine children’s mastery of the forms, whereas the language samples were used to calculate a set of language measures associated with morphological development. The study also included a group of nine children with LI between 3;11 and 9;4 years who participated in the same set of tasks as the TD children. These children were recruited from a special school in Dhaka.
Findings: The results revealed that, for both TD and LI children, the Present Simple form was acquired with highest accuracy which was followed by the scores in the Present Progressive and the Past Progressive forms respectively. The error patterns indicated a qualitative progress even in children’s errors, which was consistent with the accuracy rates of the target forms. Based on the TD children’s performance on the three tasks, a developmental sequence for the three Bangla verb forms was proposed. Results also identified that Mean length of Utterance (MLU) did not have stronger associations with the tasks scores than did Age. Among the determinants tested, Bound Morpheme Type (BMT) was identified to have the strongest associations with the task scores. Analyses of the data from the LI children revealed a significant difference between the TD and the LI children on all three tasks and the other language measures. When compared against the proposed developmental stages, the children within the LI group were found to different in terms of their morphosyntactic capacities. A sub-group of LI children also did not conform to any stages of typical development.
Conclusions: Results of the present study offer directions for future investigations in a wide range of areas of Bangla morphosyntax that need to be examined with both TD and LI children. Moreover, factors associated with language development that the present study did not examine (e.g. the role of input) also need to be addressed in future studies. Above all, there is a strong need for ongoing investigations in order to identify a comprehensive picture of morphosyntactic development of Bangla-speaking TD children, which can then lead to the assessment of a range of language impairments in Bangla.