In English as a Foreign Language (EFL) and bilingual language classrooms, code-switching is widespread among teacher-student and student-student interactions; however, there seem to be few or no studies tracking the perceptions and practices of EFL learners toward code-switching. Therefore, the aim of this study was to identify the perceptions and practices of high and low achievers toward teacher code-switching with focus on the possible limitations and benefits that it might have in language classrooms. For this purpose, the researchers used a qualitative design in the form of grounded theory. Accordingly, 11 high and 13 low achievers were interviewed individually and in focus groups. Further, the elicited responses were transcribed and codified using Straus and Corbin’s (1998) constant comparative method. In addition, for the purpose of validation, real observations of 10 university classes in different English courses were made. The findings revealed 4 major themes and 26 categories for high and low achievers. Consequently, the findings implicated that code-switching was an advantageous tool at the disposal of English teachers.
