Proto-Sino-Tibetan language

Proto-Sino-Tibetan (PST) is the linguistic reconstruction of the Sino-Tibetan proto-language and the common ancestor of all languages in it, including the Sinitic languages, the Tibetic languages, Yi, Bai, Burmese, Karen, Tangut, and Naga. Paul K. Benedict (1972) placed a particular emphasis on Old Chinese, Classical Tibetan, Jingpho, Written Burmese, Garo, and Mizo in his discussion of Proto-Sino-Tibetan.

While Proto-Sino-Tibetan is commonly considered to have two direct descendants, Proto-Sinitic and Proto-Tibeto-Burman, in recent years several scholars have argued that this was not well-substantiated, and have taken to calling the group "Trans-Himalayan". In this case, Proto-Tibeto-Burman may be considered as equivalent to Proto-Sino-Tibetan if Sinitic is indeed not the first branch to split from Proto-Sino-Tibetan.