Shifting dominance: bilingual language skills in Spanish-English bilinguals' English reading comprehension over time.

This longitudinal study investigated the relative importance of various bilingual language skills predictors for English reading comprehension over time in Spanish-English bilingual children in elementary grades. We examined the contributions of phonological awareness (PA), morphological awareness (MA), syntactic awareness (SA), and vocabulary in both English and Spanish at two time points. Dominance analysis was used to examine the shifting pattern of relative contributions of bilingual language skills to children's English reading comprehension. Results revealed a shifting dominance pattern of predictor importance over time. At Time 1, English PA was the strongest predictor, followed by English MA. However, by Time 2, English MA emerged as the most important predictor, surpassing English PA. Spanish language skills, particularly MA and PA, showed notable contributions at Time 1 but decreased in importance by Time 2. English SA and vocabulary demonstrated increasing contributions over time, while their Spanish counterparts declined. These findings highlight the evolving nature of reading comprehension predictors in bilinguals' reading development, suggesting a transition from reliance on both first and second language skills to predominantly second language-specific skills. Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s11145-026-10762-z.