1. Introduction
1. 引言
Yongxian Luo 罗永现

Abstract 摘要
1.1 AIM AND SCOPE OF THE PRESENT WORK (P. 1)
This work is a contribution to the historical-comparative study of the Tai languages. The focus is on sub grouping in the Tai family, with special attention devoted to utilizing new sources from Tai languages spoken in China’s Yunnan and Guangxi (Kwangsi) provinces. More specifically, it aims to reevaluate Fang Kuei Li’s monumental work, A Handbook of Comparative Tai (1977). The proposals put forward by Li with regards to the internal relationships of the Tai language family will be investigated and assessed in the light of a substantial body of new evidence: over 900 Tai cognate sets.

In reassessing Li’s work, this work will examine the following questions: (i) What are the workable criteria for sub grouping in the Tai languages? (ii) How and to what extent do differing criteria support the same subgroup model? (iii) In particular, in addition to phonological criteria, what dominate lexical and semantic features can be used to establish subgroups of dialects of the Tai languages? (iv) In terms of available data, what looks reasonable as a reconstructed system for PT initials? (v) To what extents does Li’s three-branch theory remain viable as a classification of Tai dialects? (vi) Can questions of Tai sub grouping benefit from historical and philological evidence, and if so, how?

The scope of this study will be limited to some correlated issues in Li’s work, namely, Li’s inventory of Proto-Tai initials, tonal irregularities, differential phonological and lexical subgroup traits, along with the plausibility of active morphophonemic process and derivational morphology in Proto-Tai. For lack of space, vowels will not be treated in detail, although attention will be given to one particular conditioned change, suggesting implications for future work. On the other hand, this study will briefly look at an extra type of sources which are not directly related to Li’s HCT and which fall outside the scope of the comparative method in its narrow sense: Chinese philological evidence for certain convergences between Tai and Chinese. A final more general aim concerns the viability of normal assumptions of historical-comparative linguistics as applied in the Tai case.