Austroasiatic from Encyclopaedia Britannica Online

also spelled  Austro-Asiatic,  
            penRelativeAssembly('2104','A','629','601')">stock of some 150 languages spoken by more than 65 million people scattered throughout Southeast Asia and eastern India. Most of these languages have numerous dialects. Khmer, Mon, and Vietnmese are culturally the most important and have the longest recorded history. The rest are languages of nonurban minority groups written, if at all, only recently. The stock is of great importance as a linguistic substratum for all Southeast Asian languages.
    

Superficially, there seems to be little in common between a monosyllabic tone language such as Vietnamese and a polysyllabic toneless Munda language such as Mundari of India; linguistic comparisons, however, confirm the underlying unity of the family. The date of separation of the two main Austroasiatic subfamilies—Munda and Mon-Khmer—has never been estimated and must be placed well back in prehistory. Within the Mon-Khmer subfamily itself, 12 main branches are distinguished; glottochronological estimates of the time during which specific languages have evolved separately from a common source indicate that these 12 branches all separated about 3,000 to 4,000 years ago.
    

Relationships with other language families have been proposed, but, because of the long durations involved and the scarcity of reliable data, it is very difficult to present a solid demonstration of their validity. In 1906 Wilhemlm Schmidt, a German anthropologist, classified Austroasiatic together with the Austronesian family (formerly called Malayo-Polynesian) to form a larger family called Austric.Paul K.Eenedict, an American scholar, extended the Austric theory to include the Tai-Kadai family of Southeast Asia and the Miao-Yao (Hmong-Mien) family of China, together forming an “Austro-Tai” superfamily.
    

Regarding subclassification within Austroasiatic, there have been several controversies. Schmidt, who first attempted a systematic comparison, included in Austroasiatic a “mixed group” of languages containing “Malay” borrowings and did not consider Vietnamese to be a member of the family. On the other hand, some of his critics contested the membership of the Munda group of eastern India. The “mixed group,” called Chamic, is now considered to be Austronesian. It includes Cham, Jarai, Rade (Rhade), Chru, Roglai, and Haroi and represents an ancient migration of Indonesian peoples into southern Indochina. As for Munda and Vietnamese, the works of the German linguist Heinz-Jürgen Pinnow on Kharia and of the French linguist André Haudricourt on Vietnamese tones have shown that both language groups are Austroasiatic.