Cao Lan language

Cao Lan, sometimes Caolan or Man Cao-Lan, is a Tai language of northern Vietnam. It is spoken by the Cao Lan subgroup of the San Chay people. According to Pittayaporn (2009),^{[full citation needed]} it is closest to the Chongzuo and Shangsi Zhuang across the border in China, both of which are lumped under the apparently polyphyletic Yongnan Zhuang by Ethnologue. Together, Cao Lan, Chongzuo, and Shangsi form a primary branch of the Tai languages (Pittayaporn 2009).