Keynote Speakers

Weera OSTAPIRAT (Mahidol University)

Mahidol University, Thailand

Kra-Dai Rimes: System and Development

In this talk, I outline a system of Proto-Kra-Dai rimes and discuss the mechanisms of vowel development including the raising, lowering, centralizing and diphthongization of the vowels. I will focus on how the basic system of four reconstructed vowels *a,*ə, *i, *u, with length distinction, has been shuffled in various Kra-Dai languages through the influence of codas and penultimate vowels. Comparative notes on the corresponding forms in Austronesian will be made.

Pittayawat PITTAYAPORN (Chulalongkorn University)

Chulalongkorn University, Thailand

Diachrony of Tones in Tai Languages

This talk provides a state-of-the-art review of research on the diachrony of lexical tones in Tai languages. First, we examine the reconstruction of Proto-Tai (PT) tones, focusing on the "three-plus-one" system and competing proposals for their origins. Second, we discuss etymological tone notation systems that facilitate cross-linguistic comparison by referencing PT tonal categories and the conditioning environments for splits. Third, we survey splits and mergers of proto-tonal categories across Tai languages, including the basic binary register split conditioned by onset voicing, as well as subsequent splits and mergers that have created diverse modern tonal systems. Fourth, we address phonetic changes in tonal contours, demonstrating that tonal developments result from both phonetically motivated internal factors and language contact.

 The titles and abstracts of these keynotes are TBA.