Effects of input on the early grammatical development of bilingual children

This study investigates the language development of 2- to 3-year-old Turkish–Dutch bilingual children with different amounts of input quan-tity. Developmental patterns in spontaneous speech data of the bilingual children are compared to those of monolingual children of the same age. It is found that low input quantity leads to slower grammatical development, but only if input is clearly reduced. The observation that not only mean length of utterance but also the development of finiteness can show pronounced delays in bilingual language acquisition contradicts maturational views of grammatical development. However, such overall delays are expected given input-based theories of grammatical acquisition. All four bilingual children show difficulties in establishing the relation between finiteness and expression of grammatical subjects in Dutch. It is argued that cross-linguistic influence, driven by surface overlap between Turkish and Dutch, may account for this observation.