A key question in the study of language representation in bilinguals is whether knowledge is shared across languages. Crosslinguistic syntactic priming has been widely used to test bilingual adults’ shared representations, but studies with child bilinguals are few and have several limitations.

We addressed these limitations in two studies with Polish–English bilingual children aged 5–11 years (N=96). We investigated bidirectional priming across languages and within each language for a structural alternation with syntactic overlap (attributive constructions) and one without structural overlap (possessive constructions).

Bidirectional crosslinguistic priming was found for possessives but not for attributives. Within-languages, there was priming for possessives and attributives in both languages. Priming was not related to children's age, vocabulary, or language dominance scores.

We show that representations can be selectively shared between languages at the construction level. The extent to which young bilinguals have shared representations depends on the frequency and complexity of structures in each language.