Purpose: With over one third of students in the United States exposed to languages other than English at home, there is a growing need to examine the role of bilingual exposure across settings on bilingual language performance. This study explored the longitudinal relationship between language exposure at home and school, and changes in bilingual oral language performance from kindergarten to first grade. Method: One hundred sixty-four Spanish–English participants who had different levels of bilingual exposure at home and school were assessed on bilingual oral language performance using a standardized language assessment in kindergarten and first grade. Caregivers and teachers reported bilingual exposure at home and at school, respectively, for both time points. Results: The results indicated that Spanish home exposure at kindergarten uniquely predicted Spanish semantics in first grade, while Spanish school exposure at kindergarten uniquely predicted Spanish morphosyntax in first grade, after controlling for kindergarten performance. No differential contributions were observed for English exposure and performance. Children with high Spanish home exposure (> 60%) had significantly higher gains in standard scores for Spanish semantics and overall Spanish performance compared to the low Spanish exposure group, but there was no significant effect on changes in English standard scores across groups. Conclusions: The current study suggests that language exposure at home and school had different contributions to bilingual home language development. This supports the importance of home and school Spanish language exposure in promoting heritage language development without compromising English.
Zhang et al. (Wed,) studied this question.