A Study On The Historical Evolution Of The Modal Category Of Tibetan Verbs

This dissertation is a historical study of the development of the modality in Tibetan.Modality is a linguistic category whose primary meaning is to reflect the situation of the proposition and express the speaker’s attitude. Modality can be devided into four types : evidential, epistemic, deontic and dynamic. Evidential modality indicates the source of the information or the way by which the information is attained. Epistemic modality indicates the possibility of the event described by the proposition, that is to say, to what extent the proposition is possible. Deontic modality is concerned with the speaker’s imperative, optative, prohibition and permission to other people. Dynamic modality means the subjective or objective ability of the agent or the subject of the clause, also including the obligation or objective necessity. Modality is usually expressed by inflection or auxiliary verbs. Modality has obviously similarity with tense and aspect with respect to form and meaning and these three categories usually have diachronic evolutionary relationship.Tibetan belongs to the Tibeto-Burman subgroup of Sino-Tibetan. It has close relationship with Baimai, Tshangla, Menba and some other languages which constitutes the Bodic group. This dissertation devides the Tibetan language into five dialects(Central, Amdo, Khams, Laddakhi and Dzongkha) and three historical phases(Old Tibetan, Classic Tibetan and Middle Tibetan). By examining the the distribution of the modality in the five dialects and three phases of Tibetan and combining the results of dialect comparison and the data of historical document corprus, this dissertation characterizes the historical development of the modality, generalizes the grammaticalization path of the modal markers and constructs the semantic map model of the modality in Tibetan.The main contents of this dissertation are as follows:Chapter 1 is the introduction to the reason of choosing this topic, the research value of this study, the theoretical framework, the source of data, and the achievements and difficulties to the analysis. Literature review on the history of the research on modality in Tibetan is also presented. Representative achievements are introduced.Chapter 2 introduces the definition and classification of the modality category. On the basis of the achievments of the linguistic typology in recent years, modality category is defined. The relationship among modality, mood and evidentiality is also discussed. The modality is divided into four types, including evidential modality, epistemic modality, deontic modality and dynamic modality. The definitions of the four types are respectively presented. This chapter also discusses the expression of modality and the relationship among modality, tense and aspect. Considering the character of Tibetan, the problem of the auxiliary verb is highlighted.Chaper 3 is an overview of the Bodic languages, Tibetan dialects and phases of Tibetan history. For Tibetan langauge, there are five dialects-- Central, Amdo, Khams, Laddakhi and Dzongkha-- and three historical phases-- Old Tibetan, Classic Tibetan and Middle Tiebtan. The classification of Bodic group is also discussed.Chaper 4 introduces the evidential modality in Tibetan. Evidentiality is an areal feature of languages in the inner Asian continent. Among these languages, the evidential modality in Tibetan has specific characteristics. The Tibetan verb has a evidential system consisted of evidentiality, mirativity and egophoric。Chapter 5 introduces the epistemic modality in Tibetan. The epistemic modality is closely related to the evidential modality. Like evidential modality, the epistemic modality is the innovation in Middle Tibetan.Chapter 6 introuduces the deontic modality in Tibetan. Unlike the evidential and epistemic modality, the deontic modality is relatively conservative. The deontic modality in modern Tibetan dialects obviously inherits from ancient Tibetan. The deontic modality in Tibetan may be genetically related to that in Bodic langauges.Chapter 7 introduces the dynamic modality in Tibetan. The dynamic modality has both conservative and innovative characteristics. On the one hand, most dynamic modal markers are derived from ancient Tibetan. On the other hand, most dynamic markers must combine with evidential markers to make up auxiliary verb constructions in clauses. These evidential markers are newly developed.Chapter 8 is conclusion. main viewpoints of this dissertation are summarized. Eight evolution principles are generalized. A semantic map of modality in Tibetan is also presented.