National audienceIn this paper, I try to show that, contrary to what one might think, left dislocation (LD : John, I like him) and fronting (also called topicalisation: John, I like) are not in complementary distribution. First of all, the notion of topicalisation, which is used to describe both structures, cannot be considered to be a common ground, since it doesn't apply to all cases of LD or fronting. Second, if we look at the discourse statuses of the left dislocated and fronted elements, we cannot say that they are complementary: LDs are not all Discourse-new, and fronted elements are not all Discourse-old. Third, if we consider the syntactic environments in which the two structures appear, they are not complementary either: even thoug...