Proceeding from the revival of linguistic interest in the rhetorical figures metaphor and metonymy and their underlying association types similarity and contiguity, the study demonstrates that metonymy is a powerful explanatory principle for many semantic phenomena in French sentence structures. First, the author shows how metonymic relations generate patterns of polysemy and are hence lexicalized in the valency of the respective verb. There follows a discussion of verb-valency restraints on the use of metonymic expressions. Here reflexive constructions etc. offer a new approach. Both perspectives reveal the primacy of the direct object for metonymic processes.