This study deals with the actancy as well as the aspectual and modal markers in Drehu, an Oceanic language spoken in the island of Lifu (Loyalty islands). It builds on the Theory of Utterance Operations as developed by A. Culioli. The first section concerns the Drehu parts of speech; the author demonstrates the polyfunctionality of Drehu lexical units and the irrelevance of a verb/noun precategorisation. The second section is devoted to the analysis of the mains mood and aspect markers. None of them expresses temporality, except when they occur without any contextual specification. Each of the aspectual and modal markers indicates a specific utterance operation. The third section, about argument structures, shows how predicates and arguments are organized along several devices, which often combine, such as constituent order and argument markers. Their use and pattern depend on the mood or aspect marker, as well as on the valency of the predicate.