Determiner use in Italian Swedish and Italian German children: Do Swedish and German represent the same parameter setting?

In this article we compare the acquisition of determiners in bilingual children acquiring Italian simultaneously with German or Swedish. We are concerned with cross-linguistic differences in the rate of acquisition and we discuss in particular the Nominal Mapping Parameter, a model according to which the syntax-semantics interface is crucial in acquisition and which predicts similar developmental patterns for children acquiring a Germanic language. We show that Swedish determiners are acquired more easily than German determiners, which implies that predictions for developmental patterns should not be based on syntactic factors alone, but must make reference to typological differences in morphology and phonology. Furthermore, we show that the acquisition of Italian determiners is affected positively by the simultaneous acquisition of Swedish but that no such effect arises when Italian is acquired simultaneously with German.