Code switching is one of the major themes in bilingual studies. Bilinguals/multilinguals code switch in a perfect ease between languages and dialects of the same language. This study investigates the variety of languages chosen in Tunisian business companies for oral and written communication. It focuses on the social constraints on code switching between Arabic (Modern Standard Arabic and Tunisian Arabic), French and English. It also presents the complex linguistic situation in terms of the different motivations for code switching between in-group members and also with foreign colleagues and...