Japanese and English Code-Mixing: A Study on the Grammar and Functions by L1 Japanese-Speakers in Oregon

This thesis examines the phenomenon of code-mixing (CM) among speakers of Japanese as their first language (L1) and of English as their second language (L2) residing in Oregon, the United States. Unlike prior studies that focus on early bilinguals or individuals with mixed linguistic and cultural backgrounds, this study specifically target speakers who began learning English in formal settings through compulsory education or a cram school in Japan. After they had completed high school in Japan, they started living in English-speaking countries. The participants in this study were two communities. Each group recorded their conversations via their own cell phones, and sent the audio files to the researcher. The instances of CM utterances were transcribed and identified by the researcher, and the cases were categorized based on Muysken's (2000) classification. The results revealed that speakers solely employed insertional CM, and there was a complete absence of inter-sentential CM and alternational CM. Furthermore, the vast majority of inserted English items were recategorized into nouns within the matrix Japanese structure from other parts of speech. A number of CM functions were analyzed and appeared to serve communicative purposes such as clarifying meanings, emphasizing a message, and conveying accuracy when quoting. Overall, the participants' CM exhibited distinctive features that differed from those observed in previous CM research. The speakers consistently integrated the English CM into Japanese phonologically and adhered to Japanese as the morphosyntactic base. Despite following the Japanese matrix system, participants utilized English CM items at the semantic and pragmatic level to broaden their range of expressible meanings.