Dominance-Driven Facilitation in Greek–English Sequential Bilingual Children's Use of Infinitival 'To'

Crosslinguistic influence (CLI) is a well-studied topic in the field of second language (L2) acquisition. CLI depends on the degree of structural overlap between the two languages: partial overlap might lead to negative influence, while complete overlap might lead to positive influence (facilitation). Facilitation has received comparatively little attention, particularly in the context of sequential bilingual children who pick up their second language after their first language has developed. The present study aimed to address this gap by exploring the use of infinitival ‘to’ (i.e., 'to' in 'I want to go') in Greek-English sequential bilingual children. 140 5-year-old participants (34 Greek monolingual, 36 English monolingual and 70 Greek-English bilingual, of whom 35 attended a total immersion programme and 35 attended a partial immersion programme in Greece) completed an oral language production task in English and/or Greek. Children in total immersion performed on par with their English monolingual counterparts, suggesting a degree of facilitation from the L1 to the L2, but children in partial immersion were less accurate in their production of the structure in English. These findings are attributed to linguistic dominance, which emerged as a significant predictor of children’s accuracy in the task, highlighting that the educational programme children attend, and therefore their exposure to the L2, matters more than overall linguistic proficiency when it comes to the acquisition of infinitival ‘to’.