AbstractA study on language alternation despite its pervasive presence in the academia, can never be exhaustive. Given the complexities of the geography in which the English language transcends many language boundaries, modern studies of code switching present various facets of this bilingualism phenomenon. Adding to this, the present study explores the employment of code switching (CS) by a non-English as Second Language (non-ESL) content instructor in a Malaysian tertiary institution that uses English as a medium. It looks at (i) the language choice and utterances, and (ii) the syntactical features of the code-switched lecture by this non-ESL content instructor. In addition, the main reasons for the instructor’s language choice are also provided. A self-taped business studies lecture with a duration of 75 minutes is used for this study. The audio transcription then is categorised into 4 types of utterances namely (i) English, (ii) Malay (iii) Arabic and (iv) Code-Mixed. Syntactical analysi.....