Intentional and Unintentional Code-Switching in Chinese-English Bilinguals: Motivations and Effects

Bilingual communication involves both intentional and unintentional language choices, yet the underlying motivations and their effects remain understudied. Code-switching – the alternating use of multiple languages within a single interaction – is a distinctive feature of bilingual speech, reflecting both deliberate and automatic language processes. While extensive research has examined this phenomenon from structural-linguistic, psycholinguistic, and sociolinguistic perspectives, less effort has been devoted to examining speakers’ underlying intentions. This dissertation aims to provide a systematic discussion on the motivations behind unintentional and intentional code-switching and to establish the connection between intentionality and structural and social aspects. We first established a taxonomy differentiating unintentional and intentional code-switching based on theoretical assumptions and existing literature. Next, we applied our classification scheme to a publicly available corpus of Chinese-English bilingual conversations, as well as data collected from lab experiments and instructional settings. We explored whether differences exist in structural characteristics of unintentional and intentional code-switching. Furthermore, we took the addressees’ perspective and investigated whether unintentional and intentional code-switching facilitates or hinders comprehension, focusing on response accuracy and speed. We also engaged both speakers and addressees in collaborative tasks to examine the intricate interplay between conveying and interpreting intentions through code-switching. This dissertation provides valuable insights into the role of language in self-expression, information communication, and collaboration among speakers, highlighting how intentionality influences linguistic structure, cognitive processing, and social interactions through the lens of bilingual code-switching. By offering a novel perspective on intentionality in communication, this research contributes to the study of bilingualism while affording recommendations for effective instructional approaches in bilingual educational contexts.