Subordination in Turkish Heritage Children with and without Developmental Language Impairment

A large body of cross-linguistic research has shown that complex constructions, such as subordinate constructions, are vulnerable in bilingual DLD children, whereas they are robust in bilingual children with typical language development; therefore, they are argued to constitute a potential clinical marker for identifying DLD in bilingual contexts, especially when the majority language is assessed. However, it is not clear whether this also applies to heritage contexts, particularly in contexts in which the heritage language is affected by L2 contact-induced phenomena, as in the case of Heritage Turkish in Germany. In this study, we compare subordination using data obtained from 13 Turkish heritage children with and without DLD (age range 5; 1–11; 6) to 10 late successive (lL2) BiTDs (age range 7; 2–12; 2) and 10 Turkish adult heritage bilinguals (age range 20; 3–25; 10) by analyzing subordinate constructions using both Standard and Heritage Turkish as reference varieties. We further investigate which background factors predict performance in subordinate constructions. Speech samples were elicited using the sentence repetition task (SRT) from the TODİL standardized test battery and the Multilingual Assessment Instrument for Narratives (MAIN). A systematic analysis of a corpus of subordinate clauses constructed with respect to SRT and MAIN narrative production comprehension tasks shows that heritage children with TD and DLD may not be differentiated through these tasks, especially when their utterances are scored using the Standard Turkish variety as a baseline; however, they may be differentiated if the Heritage Turkish is considered as the baseline. The age of onset in the second language (AoO_L2) was the leading performance predictor in subordinate clause production in SRT and in both tasks of MAIN regardless of using Standard Turkish or Heritage Turkish as reference varieties in scoring.