Overview
The languages of East Asia belong to several distinct language families, with many common features attributed to interaction. In the Mainland Southeast Asia linguistic area, Chinese varieties and languages of southeast Asia share many areal features, tending to be analytic languages with similar syllable and tone structure. In the 1st millennium AD, Chinese culture came to dominate East Asia, and Classical Chinese was adopted by scholars and ruling classes in Vietnam, Korea, and Japan. As a consequence, there was a massive influx of loanwords from Chinese vocabulary into these and other neighboring Asian languages. The Chinese script was also adapted to write Vietnamese (as Chữ Nôm), Korean (as Hanja) and Japanese (as Kanji), though in the first two the use of Chinese characters is now restricted to university learning, linguistic or historical study, artistic or decorative works and (in Korean's case) newspapers, rather than daily usage.
Language families
The Austroasiatic languages include Vietnamese and Khmer, as well as many other languages spoken in areas scattered as far afield as Malaya (Aslian) and central India (Korku), often in isolated pockets surrounded by the ranges of other language groups. Most linguists believe that Austroasiatic languages once ranged continuously across southeast Asia and that their scattered distribution today is the result of the subsequent arrival of other language groups.
One of these groups were the Tai–Kadai languages such as Thai, Lao and Shan. These languages were originally spoken in southern China, where the greatest diversity within the family is still found, and possibly as far north as the Yangtze valley. As Chinese civilization expanded southward from the North China Plain, many Tai–Kadai speakers became sinicized, while others were displaced to Southeast Asia. With the exception of Zhuang, most of the Tai–Kadai languages still remaining in China are spoken in isolated upland areas.
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