International audienceIn this paper, we study two morpho-syntactic patterns in Ancient Greek and in Modern Greek, i.e. the subjunctive with the modal particle in Ancient Greek and the bare perfective non past form (sometimes called “subjunctive without να”) in Modern Greek. The patterns share syntactic and semantic proprieties, which define a linguitic category, the presumptive (Fr.“éventuel”, M.Gr ενδεχόμενο). We show how consistent is the category in both languages, and particularly in relative clauses, beyond the differences which come from two different synchronic systems.RESUME.-Dans cette étude sont comparées deux configurations morpho-syntaxiques du grec ancien et du grec moderne, d'un côté le subjonctif accompagné de la particule mo...