It is not possible to explain what happens to French syntax in a situation of close contact with one or more languages, solely in terms of French. How then can we describe French in relation to the languages in contact? We first discuss the early research of Gabriel Manessy and their development by a number of linguists, and later show the importance of exploring several properties of the constructions under study in comparing languages, in order to place them within the context of general language processes. Furthermore, we will insist on the need to go beyond the forms at issue by focusing on their behavior. The examples will be taken from Ivory Coast French, which, ever since its establishment, has been in contact with the languages of the vast Niger-Congo family, in particular Jula and Baule (which have themselves been in contact for several centuries).