Northwestern China (Xīběi 西北) is a geographic term which refers to the provinces of Shǎnxī, Gānsù and Qīnghǎi, and the two autonomous regions Níngxià and Xīnjiāng. Sporadically, it also refers to parts of Inner Mongolia. It is one of the rare regions where a very wide range of language varieties of different structural types and genetic families co-exist. Besides Hàn 漢 Chinese (also called Pǔtōnghuà 普通話 'Mandarin') and Tibetan (Zàngyǔ 藏語), two major languages in the Sinitic and Bodic families of languages (they are also classified together as Sino-Tibetan language…