Kra-Dai and Austronesian

Austro-Tai is the name given to the hypothesis that the Austronesian language family and the Tai-Kadai language family are genetically related. Austronesian languages are primarily spoken in Taiwan, islands of Southeast Asia and the Pacific, while Tai-Kadai languages are spoken in mainland Southeast Asia, South China, and Assam (India). Lexical similarities between Tai languages and Austronesian was recognized by Schlegel in 1901. However, the hypothesis that Tai-Kadai linguistic stock to which Tai languages belong is genetically related to Austronesian was first proposed by Benedict in 1942, suggesting that their relationship was a sister relationship. This insinuates that Tai-Kadai languages and Austronesian languages evolved from a parent language that's named as Proto-Austro-Tai. Pre-Austronesian then split from Proto-Austro-Tai and moved to Taiwan where it developed independently. In 1993, Laurent Sagart published a dozen putative cognates between Chinese and Austronesian, claiming that the two languages are genetically related. At that time, his view was that Tai-Kadai was a sub-group of Sino-Tibetan and thus it belonged to this Sino-Austronesian stock. In 2005, Laurent Sagart changed his proposal to connect Tai with Austronesian rather than with Sino-Tibetan, although he still maintains that Sino-Tibetan and Austronesian are genetically related. In this new proposal, he argues that Tai-Kadai is a sub-branch of Austronesian. In the same year (2005), weera Ostapirat presented a convincing evidence for a genetic link between Kra-Dai (as he calls Tai-Kadai) and Austronesian. Ostapirat suggests that the relationship between these two language families is a sister relationship.

Lexical items showing the genetic relationship between Austronesian
and Kra-Dai (Ostapirat 2013)

English	Austronesian	Kra-Dai
Blood	daRaq	pɤla:c
Bone	CuqelaN	Kudɤ:k
Ear	Caliŋa	qɤrɤ:
Eye	maCa	maTa:
Hand	(qa)lima	(C)imɤ:
Nose	ujuŋ>ijuŋ	(ʔ)idaŋ
Tongue	Sema	(C)əma:
Tooth	nipen	lipan
Dog	asu	Kama:
Fish	Sikan	bala:
Horn	(quRuŋ)	Paqu:
Louse	KuCu	KuTu:
Fire	Sapuj	(C)apuj
Stone	batu	KaTi:l
Sun	qalejaw	Kada:w 'star'
Water	daNum	(C)aNam
I	aku	aku:
Thou	iSu, Simu	isu:, amɤ:
One	isa/esa	itsɤ:
Two	duSa	sa:
Die	ma-aCay	maTa:j
Name	ŋajan	(C)ada:n
Full	penuq	pəti:k
New	baqeRuh	(C)ama:l

Ostapirat once concluded that: "It does not seem likely that the very high number of roots between Kra-Dai and Austronesian that emerge from the core list could be accidental or simply result from borrowings". In commenting on Thurgood's claims that there are no regular sound correspondences between the Kra-Dai and Austronesian families, Ostapirat explained that they are the result of Thurgood's being unaware of crucial data from little known languages, and of the inadequacy of some of his Proto-Kra-Dai reconstructions.