Varlıklara atıfta bulunma ve bilgi kaynağını aktarma: Çocukların iletişim becerilerinin gelişimi

This thesis investigates the development of Turkish-speaking children's communicative skills by examining development of referential communication skills and the acquisition of evidentiality and relative clauses in language via experimental and corpus-based approaches. In Chapter I, we manipulated the degree of informativeness of adults' descriptions of referents in input to children and tested how hearing these descriptions affected the way children formed and repaired their own referential expressions. We further examined the link between children's cognitive skills (short-term and working memory, cognitive flexibility, and theory of mind) and referential communication skills. Children who heard more informative expressions showed a greater increase in uniquely identifying initial descriptions than children who heard less informative expressions. The ability to repair ambiguous messages was found to be related to children's memory skills and cognitive flexibility. In Chapter II, we investigated the acquisition of relative clauses, which are complex language structures that refer to entities with modifiers. We used longitudinal child-caregiver and cross-sectional peer interactions to examine the age of emergence and patterns of use of relative clauses in child speech in relation to child-directed speech and in comparison to other languages. Findings indicated that relative clauses are acquired late in Turkish compared to other languages where corpus studies are available. Although children's use of relative clauses was highly similar to adults' use in terms of the frequency distribution of the syntactic role of the head noun in the relative clause and the matrix clause, children's productions were lower in complexity indicating a gradual developmental process. Finally, in Chapter III, we studied the acquisition of the evidential marker –mIş by examining longitudinally collected child-caregiver interactions. By charting individual differences in child and caregiver speech over time with growth curve analyses, we showed that children followed a similar course of acquisition in terms of the frequency of use of the evidential marker despite differences in caregiver input. Children exhibited differences with respect to the order of emergence of different evidential functions (e.g., inference, hearsay), where each child showed a unique pattern irrespective of the frequency in the input. The use of the pragmatic functions of the evidential marker in child-directed speech depended on parental education. Overall, in this thesis we showed that (1) children's cognitive skills play an important role in their communication skills, (2) how children use language is affected by adults' use of language both in short term (as shown in Chapter I) and long term (as shown in Chapters II and III), (3) language input provided by the caregivers shows differences with respect to parental education, and (4) the development of complex language structures is gradual and not an all-or-none accomplishment.