Research has begun to address the question of transfer of language usage patterns beyond the idea that people's native language (L1) can influence the way they produce a second language (L2). This study investigated bidirectional transfer, of both lexical and grammatical features, in adult speakers of English and Spanish who varied in age of L2 acquisition. Early and late learners of English watched and orally described video depictions of motion events. Findings suggest bilinguals' patterns of motion description lexically and grammatically resemble those of monolinguals in each language. However, although participants showed bidirectional lexical transfer, they displayed only L1-to-L2 grammatical transfer. Furthermore, learning L2 post-puberty affected L2 lexical choice, but both early and late L2 learners showed L2 influence on L1 lexical choice. Finally, the findings of grammatical transfer and age of acquisition were mixed. We discuss results with reference to theories of cross-language transfer.