This book posits a universal syntactic constraint (FPC) for code switching, using as its basis a study of different types of code-switching between French, Moroccan Arabic and Standard Arabic in a language contact situation. After presenting the theoretical background and linguistic context under study, the author closely examines examples of syntactic constraints in the language of functional bilinguals switching between French and forms of Arabic, proposing that this hypothesis can also be applied in other comparable language contact and translanguaging contexts worldwide. This book will be of interest to students and scholars of French, Arabic, theoretical linguistics, syntax and bilingualism.