Intonation units and functional composition in Japanese conversational discourse

This paper examines informal face-to-face, two-party conversations in Japanese in order to explore the relationship between intonation units and functional composition. Specifically, the present study investigates the preferred functional structure of substantive intonation units that convey ideas of events, states, or referents. It was found that the Japanese substantive intonation unit preferentially consists of no more than two functional components, and that those units comprised of the ideational component only are notably prevalent in the data. This suggests that speakers of Japanese prefer to communicate ideas or propositions typically by using the simplest functional structure type which consists solely of the ideational component, with none of the other components serving a coherence-creating, regulatory, or interactional function, or as an idea-linking device. This in turn means that overwhelmingly, intonation units are produced such that they serve one function at a time. The unifunctional structure of the Japanese intonation unit this study uncovered supports the claimed single nature of this prosodic unit as the basic linguistic unit of discourse production and information flow in spontaneous conversational interaction.