The !Xu language, or !Kung as it is often spelled in English, is a member of the Khoisan languages, spoken through southern Africa. !Xu is spoken particularly in a region that encompasses parts of Namibia and Botswana, and belongs to what is called the Northern group of Khoisan languages; it possesses no labial click, typical of the Southern Khoisan languages..

Linguistically, !Xu is generally termed isolating; what this means is that words' meanings are changed by the addition of other, separate words, rather than by the addition of affixes or the changing of word structure. A few suffixes exist - for example, distributive plurals are formed with the noun suffix -si or -mhi, but in the main meaning is given only by series of words rather than by grouping of affixes.

!Xu distinguishes no formal plural, and the suffixes -si and -mhi are optional in usage. The language's word order is Adverb-Subject-Verb-Object, and in this it is similar to English: "the snake bites the man" is represented by ‡'aama n!ei zhu (‡'aama - snake, n!ei - to bite, zhu - man). !Xu uses word and sentence tone contours, and has a very finely differentiated vocabulary for the animals, plants and conditions native to the Kalahari Desert, where the language is spoken. For example, the plant genus Grewia is referred to by five different words, representing five different species in this genus.

Phonemic contrasts in !Xu include the following:

  • Pulmonic - click - twa to finish vs ‡wa to imitate
    • Pulmonic consonants
      • Voiced - voiceless unaspirated - voiceless aspirated stop: da skin, ta wild orange, tha bee sting
      • Voiced - voiceless unaspirated - voiceless aspirated - ejective affricate: djau expression of surprise, tca to fetch, tshe week, tc'a to pour
      • Voiced - voiceless fricative: za to sexually insult, se to see
    • Click consonants
      • Voiced unaspirated - voiced aspirated: g!ai~ puff adder, g!hei~ tree
      • Voiceless unaspirated - voiceless aspirated: !e~ noise, !ha~ to know
      • Unaffricated - affricated release: !o behind, !xo elephant
      • Plain - glottalised release: !b to roll up a blanket, !?b rifle
      • Plain - nasalised: |i rhinoceros, n|i to sit
  • Vowels
    • Plain - nasalised: g!a rain, '\g!a~' red
    • Plain - pharyngealised: n|om springhare, n|om big talker
    • Short - long: |u to throw, |u: to put in

!Xu is slowly dying out, along with most other Khoisan languages, because of encroaching Bantu and Khoi cultures. The Herero, Nama and Tswana languages are beginning to be more commonly spoken among the !Xu, and the hunter-gatherer way of life that is typical of the Khoisan-speaking peoples is being eroded by Bantu and Khoi farming settlements.