This article assesses the impact of bilingualism on the acquisition of pronominal direct objects in French and English (clitics in French and strong pronouns in English). We show that, in comparison to monolingual children, bilingual children omit more pronominal objects for a longer period in both languages. At the same time, the development in each language spoken by the bilinguals follows the developmental asymmetry found in the language of their monolingual counterparts: there are more omissions in French than in English. It is also shown that language dominance affects the rate of omissions as there are fewer omissions in the language in which children receive more exposure, i.e. the dominant language. We analyze these results as reflecting a bilingual effect based on the retention of a default null object representation. This in turn is supported by reduced overall input for bilingual children and by language-internal input ambiguity.

This paper investigates the role of amount of current and cumulative exposure in bilingual development and ultimate attainment by exploring the extent to which simultaneous bilingual children's knowledge of grammatical gender is affected by current and previous amount of exposure, including in the early years. Elicited production and grammaticality judgement data collected from 136 English–Dutch-speaking bilingual children aged between three and 17 years are used to examine the lexical and grammatical aspects of Dutch gender, viz. definite determiners and adjectival inflection. It is argued that the results are more consistent with a rule-based than a piecemeal approach to acquisition (Blom, Polišenskà & Weerman, 2008a; Gathercole & Thomas, 2005, 2009), and that non-target performance on the production task can be explained by the Missing Surface Inflection Hypothesis (Haznedar & Schwartz, 1997; Prévost & White, 2000; Weerman, Duijnmeijer & Orgassa, 2011).

This study compares mastery of gender assignment and agreement in Italian by adult Italian–German bilinguals who have acquired two languages simultaneously (2L1), and by adult German highly proficient second language learners (L2ers) of Italian. Our data show that incompleteness in bilingual acquisition and in second language (L2) acquisition primarily affects gender assignment: the categorization of nouns and the interpretable gender feature are subject to vulnerability in the two modalities of acquisition. Overall, mastery of morpho-syntax (i.e., gender agreement) was nearly native-like for both groups of speakers, suggesting that uninterpretable features are unlikely to be subject to vulnerability in the heritage language of adult bilingual speakers and can be acquired in adult L2 acquisition. Deviances from the target in gender assignment and, to a lesser extent, in gender agreement are attributed to both language-internal (i.e., language) and language-external factors (i.e., amount of input).

The purpose of this article was to test the predictions of a speech production model of cross-linguistic influence in French–English bilingual children. A speech production model predicts bidirectional influence (i.e., bilinguals’ greater use of periphrastic constructions like the hat of the dog relative to monolinguals in English and reversed possessive constructions like *chien chapeau to refer to a dog's hat). In contrast, other explanations predict unidirectional influence from French to English. Possessive constructions were elicited from preschool French–English bilingual children as well as preschool French and English monolinguals within the same age range. The results showed bidirectional influence, consistent with a speech production model.