This paper presents an analysis on the functions carried by phrase final tones in turn-taking and dialog acts, taking into account linguistic information about the part of speech (particles and auxiliary verbs) attributed to the morphemes at phrase finals. Natural conversational speech data are segmented in inter-pause units, and each utterance unit is arranged according to the phrase final morphemes. Turn-taking functions are annotated, and tones of each phrase final are described by acoustic-prosodic features. Analysis results show a relationship between tones and turn-taking functions in most of the morphemes, while no clear relationship is found in some classes of morphemes which are final particles.