Parental reports of bilingual toddlers’ first words and grammar of Italian in majority and heritage language contexts.

This study presents the results of an investigation into the size and composition of vocabulary and early sentence formation in two groups of young bilingual children, one acquiring Italian as a majority language and the other acquiring it as a heritage language. The results show high variability in the relationship between input and vocabulary size and composition in children between the ages of 24 and 29 months, while this relationship becomes more stable in children between the ages of 30 and 37 months. The results also show that the majority of children have a larger vocabulary and produce more complex sentences in the majority language, input received in each language does not systematically correlate with vocabulary size or with production of complex grammatical structures. The results shed light on some characteristics of early simultaneous bilingual language development. Implications for practice are discussed.