This research focuses on the communication process in the presence of a French-Quebec Sign Language (LSQ) interpreter. It highlights two characteristics of the interactional structure that are specific to this type of encounter: (1) the communication situation is a three-party discussion involving six interactional configurations; (2) a super-imposition of interactions of a different nature and function typically develops. The complexity of conversational structure confirms the need to propose a schema removed from linear traditions: a triadic model, based on co-directed interaction.