The official language of Laos is Lao, which is written with an alphabet derived from a southern Indian script. The indigenous languages of Laos fall into four major groups: the Daic or Tai-Kadai languages, Mon-Khmer (a subgroup of the Austro-Asiatic languages family), Tibeto-Burman (a subgroup of the Sino-Tibetan languages family), and Hmong-Mien. A number of the languages and dialects spoken in Laos have never been properly studied by linguists. Some of these languages are spoken by only a few thousand people.