Phoneme
Numbers of phonemes in different languages

All known languages use only a small subset of the many possible sounds that the human speech organs can produce, and, because of allophony, the number of distinct phonemes will generally be smaller than the number of identifiably different sounds. Different languages vary considerably in the number of phonemes they have in their systems (although apparent variation may sometimes result from the different approaches taken by the linguists doing the analysis). The total phonemic inventory in languages varies from as few as 9–11 in Pirahã and 11 in Rotokas to as many as 141 in ǃXũ.

The number of phonemically distinct vowels can be as low as two, as in Ubykh and Arrernte. At the other extreme, the Bantu language Ngwe has 14 vowel qualities, 12 of which may occur long or short, making 26 oral vowels, plus six nasalized vowels, long and short, making a total of 38 vowels; while !Xóõ achieves 31 pure vowels, not counting its additional variation by vowel length, by varying the phonation. As regards consonant phonemes, Puinave and the Papuan language Tauade each have just seven, and Rotokas has only six. !Xóõ, on the other hand, has somewhere around 77, and Ubykh 81. The English language uses a rather large set of 13 to 21 vowel phonemes, including diphthongs, although its 22 to 26 consonants are close to average. Across all languages, the average number of consonant phonemes per language is about 22, while the average number of vowel phonemes is about 8.

Some languages, such as French, have no phonemic tone or stress, while Cantonese and several of the Kam–Sui languages have six to nine tones (depending on how they are counted), and the Kam-Sui Dong language has nine to 15 tones by the same measure. One of the Kru languages, Wobé, has been claimed to have 14, though this is disputed.

The most common vowel system consists of the five vowels /i/, /e/, /a/, /o/, /u/. The most common consonants are /p/, /t/, /k/, /m/, /n/. Relatively few languages lack any of these consonants, although it does happen: for example, Arabic lacks /p/, standard Hawaiian lacks /t/, Mohawk and Tlingit lack /p/ and /m/, Hupa lacks both /p/ and a simple /k/, colloquial Samoan lacks /t/ and /n/, while Rotokas and Quileute lack /m/ and /n/.
startend:quotation, language:response_language[French], oulipo:avoid_letter[e]