Sino-Tibetan languages

Sino-Tibetan
Geographic distribution:	East Asia, Southeast Asia, South Asia
Linguistic classification:	One of the world's primary language families
Subdivisions:	Some 40 well-established low-level groups, but no agreement on higher-level groupings
ISO 639-2 / 5:
Linguasphere:	79- (phylozone)
Glottolog:	sino1245
Major branches of Sino-Tibetan:   Chinese   Tibetan   Lolo-Burmese   Karen   others

The Sino-Tibetan languages, in a few sources also known as Tibeto-Burman or Trans-Himalayan, are a family of more than 400 languages spoken in East Asia, Southeast Asia and South Asia. The family is second only to the Indo-European languages in terms of the number of native speakers. The Sino-Tibetan languages with the most native speakers are the varieties of Chinese (1.3 billion speakers), Burmese (33 million) and the Tibetic languages (8 million). Many Sino-Tibetan languages are spoken by small communities in remote mountain areas and as such are poorly documented.

Several low-level groupings are well established, but the higher-level structure of the family remains unclear. Although the family is often presented as divided into Sinitic and Tibeto-Burman branches, a common origin of the non-Sinitic languages has never been demonstrated, and is rejected by an increasing number of researchers.

A genetic relationship between Chinese, Tibetan, Burmese and other languages was first proposed in the early 19th century, and is now broadly accepted. The initial focus on languages of civilizations with long literary traditions has been broadened to include less widely spoken languages, some of which have only recently, or never, been written. However, the reconstruction of the family is much less developed than for families such as Indo-European or Austroasiatic. Difficulties have included the great diversity of the languages, the lack of inflection in many of them, and the effects of language contact. In addition, many of the smaller languages are spoken in mountainous areas that are difficult to access, and are often also sensitive border zones.

During the 18th century, several scholars had noticed parallels between Tibetan and Burmese, both languages with extensive literary traditions. Early in the following century, Brian Houghton Hodgson and others noted that many non-literary languages of the highlands of northeast India and Southeast Asia were also related to these. The name "Tibeto-Burman" was first applied to this group in 1856 by James Richardson Logan, who added Karen in 1858. The third volume of the Linguistic Survey of India, edited by Sten Konow, was devoted to the Tibeto-Burman languages of British India.