En (autonym: aiɲ˥˧; also known as Nùng Vên) is a Kra language spoken in Vietnam. Before its discovery in 1998, En language was undistinguished from Nùng, which is a Central Tai language closely related to Zhuang. In the late 1990s, Vietnamese linguist Hoàng Văn Ma had first recognized that it was not a Tai language, ultimately leading to field work distinguishing En as a separate language. Researchers have determined En to be one of the Buyang languages.
The speakers of En live in northern Vietnam near the border with Jingxi County, Guangxi. In 1998, En speakers were found 12 km to the east of Hà Quảng city in Nội Thôn village, Hà Quảng District, Cao Bằng Province.
- En at Ethnologue (18th ed., 2015)
- Hammarström, Harald; Forkel, Robert; Haspelmath, Martin; Bank, Sebastian, eds. (2016). "En". Glottolog 2.7. Jena: Max Planck Institute for the Science of Human History.
- Li Jinfang [李锦芳]. 2006. Studies on endangered languages in the Southwest China [西南地区濒危语言调查研究]. Beijing: Minzu University. page 90.
- Diller, Anthony, Jerold A. Edmondson, and Yongxian Luo ed. The Tai–Kadai Languages. Routledge Language Family Series. Psychology Press, 2008.