This longitudinal study investigates the changes in bilingual oral language proficiency and home language and literacy practices of young Chinese American and Mexican American dual language learners (DLLs) before and during the COVID-19 pandemic. Given that DLLs represent a significant portion of young children in the U.S., often facing socioeconomic challenges, understanding their language development is crucial. The pandemic’s considerable impact on the educational trajectories of low-income immigrant communities is of particular concern. The sample comprised 132 DLLs (41 Mexican Americans and 91 Chinese Americans) from low-income immigrant families. Data on oral language proficiency in English and the home language and home literacy practices were collected before the pandemic and again 1.5 years later. Despite school closures, both groups showed improved oral language proficiency and shifts in home literacy practices over time. This study reveals distinct relationships between home literacy practices and oral language proficiency in the two immigrant groups.

The role of dual language exposure in children's cognitive development continues to be debated. The majority of the research with bilingual children in the US has been conducted with children becoming literate in only one of their languages. Dual language learners who are becoming literate in both their languages are acutely understudied. We compared dual language learners (n = 61) in a Spanish–English dual language immersion program to monolingual English speaking children (n = 55) who were in a traditional English only school. Children (kindergarten to 3rd grade) completed standardized vocabulary tasks and two measures of executive functions. Despite having significantly smaller English vocabularies, the dual language learners outperformed the monolingual children on the executive function measures. Implications for our understanding of the relations between oral language development and executive function in bilingual children are discussed.