Japanese-English bilingual first language acquisition-two longitudinal studies

本研究探讨了同时学习两种不同类型语言的双语者的非主导语言是否与学习两种语言相近的单语者和/或双语者的非主导语言发展方式相似。我们从童年早期（2009年）到青春期晚期（2001年）对一位日英双语者进行了纵向跟踪调查，从语言学和叙事的角度研究了她的次要语言——英语。口头收集的数据在流畅性、准确性、复杂性和词汇量方面进行了分析，并观察了行动和意识的景观。研究结果表明，在核心语言区域，小语种的发展与单语种的发展相似或相同，同时习得两种语言的儿童（双语第一语言习得或BFLA）即使在接触小语种有限且两种语言在类型上彼此距离较远的情况下，也能够发展出两种独立的语言，这在一定程度上支持了独立发展假说。双语儿童表现出一些特殊的错误和独特的叙事风格，这只是部分原因，这可能是由于母语的影响。研究结果还表明，在某个年龄或之前，广泛和密集地接触小语种可能是达到与单语相近水平的必要条件。

This study explores whether the non-dominant language of a bilingual who is acquiring two typologically different languages simultaneously, develops in a similar manner to monolinguals and/or bilinguals who are learning two linguistically close languages. We tracked a Japanese-English bilingual longitudinally from early childhood (4;09) into late adolescence (19;01) to examine her minor language, English, from both linguistic and narrative perspectives. Data collected orally were analyzed in terms of fluency, accuracy, complexity, and vocabulary as well as looking at the landscapes of action and consciousness. The results indicate that the development of the minor language is similar or identical to that of a monolingual in core linguistic areas, and that a child acquiring two languages simultaneously, (bilingual first language acquisition or BFLA) is able to develop two separate languages even when exposure to the minor language is limited and the two languages are typologically distant from each other-partially supporting the Separate Development Hypothesis. It is only partial since the bilingual child showed some idiosyncratic errors and a unique narrative style, which is possibly due to L1 influence. The results also imply that extensive and intensive exposure to the minor language at or before a certain age may be essential to reach the level similar to a monolingual.