In this article, I challenge the generally well-accepted idea that constructions with support verbs in Medieval French are “frozen expressions”. My objective is to show that these support verb constructions in Middle French (14th-15th centuries) are, in fact, cases of free syntax, even if it is observed that the nominal predicate appearing in these structures is often a bare noun. Only in some cases can a support verb construction appear to be frozen : to be precise, when the article preceding the noun cannot vary, and when the noun’s meaning is opaque.