The effect of bilingualism on foreign language learning: A longitudinal study from kindergarten to the end of primary school

This study examined whether bilingual children outperform monolingual peers in English as a foreign language (EFL) from kindergarten through primary school, and how their learning trajectories compare over time. A total of 691 monolingual children and 193 bilingual children in the Netherlands participated. English vocabulary and grammar skills were assessed at four timepoints: kindergarten, Grade 1, Grade 3, and Grade 6. Control variables included English exposure outside school, parental education, attitudes toward learning English, non-verbal IQ, child age, gender and school type (bilingual vs. mainstream). Results showed that bilingual children outperformed monolingual peers in both vocabulary and grammar in kindergarten and Grade 1. However, these differences disappeared by Grades 3 and 6. Growth analyses indicated that monolingual children exhibited faster progress across primary school compared to bilingual children. These findings point to an early bilingual effect in English, followed by a catch-up effect among monolingual children in the later primary years.