Functions of EFL Teachers’ Code-Switching in Online Courses: Insights from the Analysis of a Chinese-English Translation MOOC Through Adaptation Theory

Over the past decade, research on code-switching has primarily focused on English teaching in traditional classrooms, with little attention to online environments. This study addresses this gap by examining English teachers’ code-switching practices in online courses on the Massive Open Online Courses (MOOCs) platform in China. Using a Chinese-English Translation MOOC as a case study, this study employed a conceptual framework that combines adaptation theory with the Matrix Language Frame model to analyze the linguistic, interpersonal, and class management functions of code-switching. This analysis includes adaptations to language reality, students’ comprehension, teachers’ mental motivation, and their roles in class management. Analysis of the data, which involved coding the transcripts of six lecture recordings from the Chinese-English Translation MOOC, revealed diverse uses of code-switching. It was predominantly used for interpersonal functions, such as adapting to teachers’ mental motivation. Less frequently, it was used to adapt to the teachers’ roles. The least common was adaptation to students’ receptive abilities. The findings indicate that code-switching practices in the context of MOOC teaching align with the specific communication needs of virtual teaching environments.