official language of Vietnam, spoken in the early 21st century by more than 70 million people. It belongs to the Viet-Muong subbranch of the Vietic branch of the Mon-Khmer (Mon-Khmer languages) family, which is itself a part of the Austroasiatic stock. Except for a group of divergent rural dialects (dialect) spoken between Hue and Vinh, most of the dialects of Vietnamese differ from each other to about the same degree as do the dialects of English in the United States. The standard language is based on the speech of educated people living in and around Hanoi. A large proportion of the vocabulary of Vietnamese has been borrowed from Chinese, and the influence of Tai languages is also evident. See Austroasiatic languages.

Characteristics of Vietnamese include the use of tones to distinguish words with identical consonant and vowel sequences, the use of word order to express the syntactic relations of words to each other, and the use of modifiers rather than affixes to express the tense and voice of verb forms.