In this seminar I present the morphosyntactic development of two typologically different languages, Japanese and English, of one child who was raised in these languages from birth. Issues in the field of bilingual first language acquisition (BFLA) include whether the two languages in a bilingual child develop separately from the beginning , as represented by De Houwer's (1990) Separate Development Hypothesis (SDH). Evidence obtained from past studies of BFLA (e.g., De Houwer, 1990, 2009; Meisel, 1990; Mishina-Mori, 2002) supported the SDH. These studies examined whether BFLA occurs in the same manner as monolingual first language acquisition. They did not compare the development of two different languages directly.
The present study was conducted within the framework of Processability Theory (PT) (Pienemann, 1998, 2005) to investigate the developmental path of each language of a child. Further PT was used as a common point of reference for a direct comparison of the development of two typologically distant languages. Data for the study consisted of the child's naturally occurring spontaneous unilingual speech in both languages, collected by audio- and video recording from the time the child was 1;11 (one year and 11 months old) until 4;10.
It was found that the two languages of the child followed the developmental hierarchy predicted by PT, i.e., they both developed in the order of word > lexical procedure > phrasal procedure > inter-phrasal procedure. However, the procedural stages did not emerge at the same time across languages. These results further support the SDH of bilingual first language acquisition.
De Houwer, A. (1990). The acquisition of two languages from birth: A case study. Cambridge: Cambridge University Press.
De Houwer, A. (2009). Bilingual First Language Acquisition. Clevedon/Buffalo: Multilingual Matters.
Meisel, J. M. (Ed.). (1990). Two first languages: Early grammatical development in bilingual children. Dordrecht: Foris.
Mishina-Mori, S. (2002). Language differentiation of the two languages in early bilingual development: A case study of Japanese. International review of applied linguistics, 40, 211-233.
Pienemann, M. (1998). Language Processing and Second Language Development : Processability Theory. Amsterdam: John Benjamins.
Pienemann, M. (Ed.). (2005). Cross-linguistic aspects of processability theory. Amsterdam: John Benjamins.