A model of the origin of Kra-Dai tones

This paper finds origins for the three Kra-Dai tones in the segmental endings of Proto-Southern Austronesian, the parent language of Kra-Dai and Malayo-Polynesian. The Kra-Dai A category originates in sonorant endings (vowels, semi-vowels, nasals, liquids) and in Proto-Austronesian *-H2, reconstructed by Tsuchida (1976); the B category in *-R and in *-X, a hitherto not reconstructed ending reflected as -h in Amis and in the Bisayan language Aklanon; the C category, in Proto-Austronesian *-H1, reconstructed by Tsuchida. The tonal outcomes of *-s and *-S are described. Kra-Dai sonorant endings in tone C are argued to come from hypothetical Austronesian prototypes in which a sonorant ending was followed by *-s, a suffix of unknown function. Although the present model does not require Kra-Dai to be a daughter of Proto-Austronesian, the building blocks for Kra-Dai tones are shown to be in place during the Formosan phase of Austronesian phonological history.