The Nung speak a Central Tai language that is related to Southern Zhuang (China) and Tay.  This is a completely different language group from Vietnamese, which is of the Mon-Khmer group.  The Nung language has at least 9 dialects.

The Nung are also different from Chinese Nung (Cantonese) and Tibeto-Burman Nung (Nu).  Some groups called Nung in South Vietnam, in particular, are Cantonese Chinese, and not related to the Nung group discussed here.

      Nung is a part of the Central subdivision of Tai, which is a component of the Tai-Kadai language    The Nung has a written script called Nom Nung (Nung demonic script) which has been used since the 17th century, if not longer.  Ropal code for the Nung language: NUT00