text: The Tày people, also known as the Thổ, T'o, Tai Tho, Ngan, Phen, Thu Lao, or Pa Di, are a Central Tai-speaking ethnic group who live in northern Vietnam. According to a 2009 census, there are 1.7 million Tày people living in Vietnam. This makes them the second largest ethnic group in Vietnam after the majority Kinh (Vietnamese) ethnic group. Most live in northern Vietnam in the Cao Bằng, Lạng Sơn, Bắc Kạn, Thái Nguyên, and Quảng Ninh provinces, along the valleys and the lower slopes of the mountains. They also live in some regions of the Bắc Ninh and Bắc Giang provinces. They inhabit fertile plains and are generally agriculturalists, mainly cultivating rice. They also cultivate maize, and sweet potato among other things.
  History
  The Tày were once known as the Thổ people.  is derived from Chinese  (), which means 'land' and 'local'. Although not inherently a pejorative it was often used as such in practice (cf. "bumpkin") in both Vietnam and China. Under the Socialist Republic of Vietnam, Thổ was deemed a pejorative and substituted with Tày.
  The Tày are closely related to the Nùng people and Zhuang people, who they are culturally and linguistically almost indistinguishable from. Although they are considered an indigenous group, portions of their population likely originated in China during the 11th and 12th centuries. However unlike the Nùng, they were more heavily Vietnamized due to their closer proximity to the Kinh and shared similar cultural practices with the Vietnamese such as lacquering their teeth black. By 1900 around 30% of their language was made of Vietnamese loan words.