Influences of early and intense L2 exposure on L1 causal verb production: Comparison of 5-, 7-, and 9-year-old bilingual and monolingual children

This study investigates the influences of early and intense L2 exposure on children’s L1 causative verb production, assessed by an experimental causative verb production task. Turkish expresses causality by morphological and lexical means, whereas English does so by periphrastic and lexical means. Learning L2 English might enhance L1 Turkish causative verb production by highlighting the parallels and contrasts in causal expressions between the languages, which may result in an enriched L1 causative use. Five-, 7 -, and 9-year-old L1-Turkish L2-English bilingual ( n = 80) and L1-Turkish monolingual ( n = 80) children participated in the study in L1-Turkish. Results indicated that language group differences only emerged for the use of morphological causative verbs in favor of 5-year-old bilinguals compared with monolingual peers. Age group differences occurred only for the monolingual group and only for morphological verbs. Specifically, monolingual 7- and 9-year-olds performed better than monolingual 5-year-olds. Causative verb-type differences were only seen for 5-year-old monolinguals, who performed better for lexical than morphological verbs; in contrast, 5-year-old bilinguals performed equally well on the two types of causatives, and better than 5-year-old monolinguals on morphological causatives. Overall, these findings indicate that learning an L2 with structural similarities and differences compared with L1 might enhance children’s awareness and correct use of causal linguistic structures.