Acquisition of Turkish by heritage speakers : a processability approach

PhD ThesisThis study presents the findings of cross-sectional psycholinguistic research investigating the first-language acquisition of Turkish among heritage speakers in Germany. Studies in heritage language acquisition in the last decades have provided increasing evidence that heritage speakers do not always converge on the grammars of native speakers, which is predominantly explained in relation to estimates of reduced input and output conditions. Nonetheless, Montrul (2010) underlines the fact that estimates of input cannot be used as measurements and addresses the need for a well-established theoretical framework that will account for the development of heritage speakers’ linguistic system to explain why heritage speakers succeed - or fail - in language acquisition in the ways that they do. This study aims to fill this gap by looking at the phenomena from a developmental perspective within the formalisms of Processability Theory (Pienemann, 1998, 2005), a well-established crosslinguistic approach to acquisition based on the architecture of the human language processor, but which has not previously been applied to Turkish. This study investigated the grammatical competence of twenty-four young heritage speakers of Turkish in Germany by testing their online processing of various Turkish grammatical structures, focusing on passives and subject relative clauses. The results demonstrate that the language acquisition of Turkish heritage speakers is developmentally constrained by availability of processing mechanisms. The participants displayed a clear hierarchy in their development, with competence in the processing of basic grammatical structures that are canonically mapped, but with gaps in the processing of complex structures such as passives and subject relative clauses that are non-canonically mapped and involve long-distance dependencies. This study thus contributes important insights both to theoretical accounts of acquisition of Turkish, and to the wider study of heritage language acquisition