Southwestern Tai languages

…divided into three linguistic groups—the Southwestern, the Central, and the Northern. Thai and Lao, the official languages of Thailand and Laos, respectively, are the best known of the languages.

…in many languages of the Southwestern group. The Chinese-based system, which is employed chiefly to write songs, consists of Chinese characters, some modified since the 18th century, but it may have been in use much earlier. The other type of writing system, first attested in the 13th century, derives from…