Language of instruction (Hiebert et al., 2025)

Purpose: This longitudinal study investigated the impact of different academic programs of primary language instruction (Spanish or English) on the dual language development of Spanish–English bilingual children. Types of academic settings offered to bilingual students as well as differing views and outcomes based on language of instruction are outlined.Method: Narrative retell language samples from 90 typically developing Spanish–English bilingual children elicited across six consecutive academic semesters from the fall of kindergarten to the spring of second grade were used to estimate Spanish and English language skills (grammar and lexical diversity) longitudinally. Participants academically instructed primarily in English (n = 45) were matched to primarily Spanish-instructed participants by age, gender, maternal level of education, and family income level.Results: The estimates of conditional growth curve models indicated that bilingual children differed in their rates of Spanish and English oral language development as a function of their primary academic language of instruction. Loss of Spanish grammatical skills was estimated for English- and Spanish-instructed participants.Conclusions: A wide range of expressive language skills and differing rates and directions of growth is present in typically developing bilingual children. The language of instruction explains some of the variability seen. These take-home findings should be considered in clinical assessment of dual language learners to avoid misdiagnosis of language impairment.Supplemental Material S1. Mean length of utterances in words (MLUw), and subordination index (SI-count) descriptive statistics in Spanish and English for English- (EI) and Spanish-instructed (SI) children.Hiebert, L., Rojas, R., & Iglesias, A. (2025). Impact of academic language of instruction on Spanish and English growth and loss in bilingual children. Language, Speech, and Hearing Services in Schools, 56(3), 807–822. https://doi.org/10.1044/2025_LSHSS-24-00120