A Longitudinal Investigation of the Relations Between Emergent Bilingual Children's Language Experience and Bilingual Language Outcomes.

Purpose: This study aims to characterize Spanish-English emergent bilingual (EB) children's language experiences and to examine how these experiences contribute to their bilingual development over a 2-year period. All eB children were enrolled in dual language immersion (DLI) programs. This setting provides a unique opportunity to explore how bilingual language experiences shape bilingual language development across time. Method: Fifty-seven Spanish-English EB children participated in the study. Bilingual language skills were assessed at two time points: Time 1 (2019) and Time 2 (2021). Participants were in Grade 1 or 3 at Time 1 (Mage = 91.4 months, SD = 12.37) and Grade 3 or 5 at Time 2 (Mage = 113.43 months; SD = 14.07), respectively. Children were assessed on phonological awareness, morphological awareness, vocabulary, and syntactic awareness in both English and Spanish. Language experience was measured through child- and teacher-reported surveys. Results: Over time, teacher-reported Spanish experience at school increased and English experience decreased, while child-reported English experience at home remained stable. Except for Spanish vocabulary, significant gains were found for all language measures, indicating continuous development trajectories. Teacher-reported English experience at Time 1 positively predicted English vocabulary gains. Time 2 teacher-reported Spanish experience and child-reported English experience negatively predicted Spanish vocabulary growth, suggesting possible trade-offs. Conclusions: This study highlights the importance of balanced, high-quality bilingual experience across home and school. DLI programs support growth in multiple language domains, though Spanish expressive vocabulary may need targeted support. Findings have educational and clinical implications for assessment, early intervention, and promoting heritage language use without compromising English-language development. [ABSTRACT FROM AUTHOR]