Synchronic and diachronic studies on the Japanese Inferential system: daroo, mitai, rashii, soo, and yooda

This dissertation investigates the contemporary Japanese inferential system, in which rashii, yooda, mitai, daroo, and soo appear intertwined with each other in their uses. Due to the similarities in their uses on syntactic and pragmatic levels, researchers tend to rely on semantics to distinguish the subtle differences among the forms. Epistemic modality has been the analytical tool most commonly used to analyze the system. Despite numerous subsequent investigations into the system, grammatical analysis has hitherto not successfully explained it.;Based on analysis of data gathered for this study it concludes that previous research into the inferential system is fundamentally distorted and that the Japanese system cannot be shoehorned into a broad theoretical framework based on evidentiality and truth-value. The alternate framework to be presented comprises two levels, Inference Relevant and Inference Not Relevance, respectively. Subcategories further divide the auxiliaries into those that allow the speaker to emphasize or not emphasize inference. Therefore in the system there is a one-to-one relationship between form and meaning. For instance, if a speaker presents his inference forcefully based on a certain event, then he may choose the Inference Relevant-HIGH FOCUS auxiliary. On the other hand, if he reserves his inference because it is not newsworthy to his addressee, such as in the case of an obvious inference about the addressee, then he uses the LOW FOCUS auxiliary that is pragmatically obligatory under the circumstance.;The historical developments of the auxiliaries are also examined in the scope of subjectification. The results of this examination uncovered the noticeable increase of subjectivity of each auxiliary as its meaning changed over time. The auxiliaries in Contemporary Japanese reached the ‘expressive’ phase, resulting in the intermingling of objective and subjective inferences (i.e., daroo, mitai, rashii, and yooda). This finding enables us to explain why researchers' interpretations of speakers' objective/subjective attitude differ from one another. It also explains why the auxiliaries developed into a variety of discourse uses, e.g., ‘hedges,’ and solicitations for answer. This comprehensive study demonstrates the misapplication of the epistemic and objective/subjective modalities to the inferential system, and proposes a sounder model of their meanings and uses.