Presents a new theory of the origin of Tai-Kadai. Instead of being co-ordinate with Austronesian as Benedict argues, it is viewed as an offshoot of Proto-Austronesian, belonging to the clade which includes several of the languages of the Formosan East coast and Malayo-Polynesian. Evidence comes from lexical and morphological features in the vocabulary Thai (broadly speaking) shares with Austronesian: in particular Tai-Kadai shares with Malayo-Polynesian some characteristic innovations in the second-person pronouns.