Explanation:

Sino-Tibetan, in a few sources also known as Trans-Himalayan, is a family of more than 400 languages, second only to Indo-European in number of native speakers.The vast majority of these are the 1.3 billion native speakers of Chinese languages. Other Sino-Tibetan languages with large numbers of speakers include Burmese (33 million) and the Tibetic languages (six million). Other languages of the family are spoken in the Himalayas, the Southeast Asian Massif, and the eastern edge of the Tibetan Plateau. Most of these have small speech communities in remote mountain areas, and as such are poorly documented.