How do differences in bilingual input affect vocabulary development of a minority language? The relationship between the type of bilingual exposure and early vocabulary acquisition

Aims and objectives/purpose/research questions: This study examines the early development of receptive and productive vocabulary in a minority language (Catalan) among children aged 10 to 18 months growing up in a bilingual social context (Catalan-Spanish). The study investigates whether a lower degree of exposure to Spanish favors greater development in Catalan and explores how age influences this development. Design/methodology/approach: A total of 463 children aged 10 to 18 months participated in the study. They were distributed into three groups based on their linguistic context (Monolinguals, Social Bilinguals, and Home Bilinguals). Their receptive and productive vocabulary was measured using the Catalan adaptation of the MacArthur-Bates CDI inventory (8–18 months version). Data and analysis: The data were analyzed using SPSS to examine the effects of linguistic context on children’s receptive and productive vocabulary, with developmental differences across age groups assessed through multivariate analysis (MANOVA), followed by univariate ANOVA and Tukey’s HSD tests. The results about exposure levels show that Catalan children from a bilingual social context have a larger vocabulary than their peers, with statistically significant differences observed only in receptive vocabulary. Concerning the influence of age, we found that the linguistic context affects only receptive vocabulary in the oldest group (16–18 months). Findings/conclusions: The findings suggest that social bilingualism provides more varied and enriched linguistic input compared with other linguistic contexts, thereby fostering receptive vocabulary development. Originality: Unlike most bilingual research focusing on production, this study explores both receptive and productive vocabulary in very young children (10–18 months). In addition, it examines how different linguistic exposure contexts influence language development, addressing a gap in studies on early bilingual acquisition. Significance/implications: The implications of these findings are discussed in relation to factors such as overall vocabulary assessment, typological similarity between the languages, and the presence of cognate words. These results underscore the potential benefits for both assessment and educational intervention in Catalan-Spanish bilingual children.