Brain boosters: How bilingualism and working memory enhance children’s comprehension of which -questions

This study investigated the comprehension of which -questions among French-speaking monolingual ( n = 26) and bilingual ( n = 28) children aged 3 to 12 years, examining the roles of verbal working memory (WM) and length of exposure to an additional language (L2). We assessed comprehension of subject- and object-questions with a character-selection task, measured verbal WM with a non-word repetition task, and quantified linguistic exposure through a parental questionnaire. Results confirmed the well-known subject–object asymmetry, with object-questions posing greater difficulty than subject-questions for both groups. Additionally, verbal WM significantly impacted comprehension of object-questions among bilinguals, but not monolinguals, with higher WM associated with better performance. Importantly, it was bilinguals with longer exposure to a language other than French who demonstrated improved verbal WM, leading to increased comprehension of object-questions compared to bilingual peers with less L2 exposure. These findings underscore the crucial role of WM in language comprehension and suggest that bilingualism can confer cognitive advantages that in turn enhance complex syntactic processing.