REBUILD · Re-exposure Effect in Bilinguals under Language Development (REBUILD)-The Acquisition of Heritage Language in Returnee Children and Mutual Effects of Experience and Cognition

Many (immigrant) children are heritage speakers (HSs; bilinguals who acquire a minority language at home, different from the majority societal language in which they are growing up). Ultimate attainment of the heritage language (HL) varies considerably amongst individual HSsmuch more profoundly that what can be noted in monolingual counterpartsdespite being naturalistic natives from birth. Understanding what factors explain/predict such differences in HS outcomes is a necessary first step in assessing and, ultimately, being able to meet the educational/interventional needs for bilingual HL development. Re-exposure Effect in Bilinguals Under Language Development (REBUILD) propose a novel approach that combines offline and online methods and focuses on a severely understudied, yet crucially important group of heritage speaker bilinguals, namely returnees. Returnees are children of immigrant families who spend a significant portion of their formative developmental years (school age) in a foreign majority language context, a typical HL scenario, yet return to their native HL environment, often as older children or teenagers. This research is important for the global reality in which HL bilingualism proliferates and HL returnees increase year-on-year. Examining the development of returnees native HL from the point of re-exposure to the native environment opens up new directions. While research shows that HL bilingualism (HLB) grammatical outcomes vary significantly, findings are largely limited to contexts in which children grow up and stay in an environment where the native HL is a minority language. Environment transitionsas in the case of returneesopen an exciting opportunity to tease apart internal (grammatical structure, non-linguistic cognitive abilities) and external factors (input, use) accounting for HLB.