This article gives an account of the specificity of competing uses of pas and non (pas) in corrective sequences of the [Neg X (mais) Y] or [X (mais) Neg Y] types. With respect to the corresponding properties of negation markers, we show that there are, indeed, two clauses, even if they are averbal ones, in corrective sequences. And we also show that the choice of the marker is related to the syntactic and pragmatic relation between these two clauses: the use of pas marks an enunciative coordination, whereas non (pas), specialized in expressing contrast, marks an enunciative subordination. The use of the latter is more constrained as it underlines, in the sentence where it occurs, a conflicting link between the syntactic level and the enunciative organization.