Cross-linguistic influence in bilingual children: Can input frequency account for it?

Many researchers have observed that in the development of two grammatical systems the two languages can influence each other. This influence has been labeled cross-linguistic influence. It has been argued by some researchers that cross-linguistic influence is a child-internal process reflecting that bilingual children, when confronted with a highly complex grammatical phenomenon in one language, will use the less complex analysis of the same grammatical phenomenon in the respective other language for both languages temporarily. However, cross-linguistic influence may also be promoted or even caused by a so-called “parental contact-variety input”, meaning that child data would simply reflect a so-called “contact-variety input” of the native language of that parent who, for a long time, has lived in an L2 majority environment and thus shows some inherent cross-linguistic interference himself. The aim of the present research is to argue that a contact-variety approach cannot account for cross-linguistic influence in early bilingualism. The effects of cross-linguistic influence depend on language complexity and on the bilingual's fluency.