Tone refers to the use of pitch in language to distinguish words. All languages use intonation to express emphasis, emotion, or other such nuances, but not every language uses tone to distinguish meaning outright. When this occurs, tones are equally important and essential as phonemes (discrete sounds, for example, /t/, or /d/), and they are referred to as tonemes.

Languages that make use of tonemes are called tonal languages. The majority of languages in the world are tonal languages.

Perhaps the best-known examples of tonal languages are Mandarin and Cantonese, but in fact, many unrelated languages are tonal.

The Sino-Tibetan language group mainly consists of tonal languages, including Mandarin, Cantonese, and Tibetan. (Almost all Sino-Tibetan languages are tonal, e.g. the various Chinese languages, Tibetan, Burmese; however Newari, a language of Nepal, is non-tonal). Tonal languages have also emerged in many other language families, such as

• the Austro-Asiatic (some, e.g. Vietnamese, but others, such as Mon, Khmer and the Munda languages are non-tonal)
• the Tai-Kadai family (e.g. Thai, etc.)
• the Miao-Yao family
• some Austronesian languages (which generally are non-tonal: Malay-Indonesian, Javanese, Balinese, Cham -- the language of Indianized kingdom of Champa in southern Vietnam, Malagasy and the Polynesian languages such as Fijian, Hawaiian, Maori, Samoan, Pascuan, etc. which are the best known Austronesian languages are all non-tonal)
• some Indo-European (some Indo-European languages usually characterized as tonal, such as Lithuanian, Old Church Slavonic, Slovenian, Serbian, Croatian, are in fact pitch accent languages; Limburgian, Swedish and Norwegian may be closer to being true tone languages; Panjabi is a true tone language where the tones arose as a reinterpretation of a consonant series in terms of pitch)
• many Afro-Asiatic (Chadic, e.g. Hausa, Cushitic, and Omotic subfamilies)
• the Niger-Congo languages (most are, e.g. Wolof, Peul, Malinke, Yoruba, Twa, Lingala, Nguni -- the last two being Bantu languages, but some, e.g. Swahili, a Bantu language, are not; note: Nguni includes Zulu, Xhosa, Ndebele and Swazi)
• the Khoisan languages (all of them)
• the Athapaskan languages (e.g. Navajo and the other Apache languages; note: Athabaskan languages are often included into a larger Na-Dene family, but the reality of Na-Dene especially regarding Haida and Tlingit has been questioned) and many native language families of the Americas.

Several dead languages also incorporate tones, including Vedic Sanskrit. Some linguists have suggested that Sumerian may have had tones (presumably to try and reduce the great number of homonyms of Sumerian whose lexemes and morphemes are all monosyllabic), but that hypothesis has not been generally accepted.

(Actually Vedic Sanskrit is more often called a pitch accent language, but since a small number of words in the late pronunciation of Vedic carry the so called independent svarita on a short vowel one can argue that late Vedic was marginally a tone language. Note however that in the metrically restaured versions of the Rig Veda almost all of the syllables carrying an independent svarita must revert to a sequence of two syllables the first of which carries an anusvaara and the second a (so called) dependent svarita. Early Vedic was thus definitely not a tone language but a pitch accent language.)

Generally tone in a language is an areal, not a genetic, feature: that is, a language tends to (but does not always automatically) acquire tones if many neighboring languages also are tonal. For example it is accepted that tones in the East-Asian language area spread from the Chinese family (Sinitic) or from Tai-Kadai (more probably from Sinitic). An interesting question is how tones arise in a language. For example in Chinese they arose as a reinterpretation of initial or final consonant clusters as a pitch inflection of the vocalic nucleus of syllables. (It is known, in all languages, that surrounding consonants influence the pitch of the adjacent vowel). The same thing happened for Vietnamese (probably under the influence of Chinese; note that Khmer, which is genetically related to Vietnamese, is not a tonal language). This mechanism seems to account for the appearance of contour tones. In the Algonquian language Cheyenne, tone arose via vowel contraction; the long vowels of Proto-Algonquian contracted into high-pitched vowels in Cheyenne, while the short vowels became low-pitched.

Most languages use tone (that is, pitch) to convey grammatical structure or emphasis (see phonology), but this does not make them tonal languages in this sense. In these cases, tones can change how the audience is intended to interpret a word (e.g. sarcastically), but in tonal languages, the tone is an integral part of a word itself. Thus minimal pairs can exist in such a language, distinguished only by a change of tone.

To illustrate how tone can affect meaning, let us look at the following example from Mandarin, which has five tones:

• 1 is a long, high level tone.
• 2 starts at normal pitch and rises to the pitch of tone 1.
• 3 is a low tone, dipping down briefly before slowly rising to the starting level of tone 2.
• 4 is a sharply falling tone, starting at the height of tone 1 and falling to somewhere below tone 2's onset.
• . (dot) or 5 or 0 is a neutral tone, with no specific contour; the actual pitch expressed is directly influenced by the tones of the preceding and following syllables. Mandarin speakers refer to this tone as the "light tone" (輕聲).

These tones can lead to one syllable, e.g. "ma", having five meanings, depending on the tone associated with it, so that "ma1" glosses as "mother", "ma2" as "hemp", "ma3" as "horse", "ma4" as "scold", and "ma5" at the end of a sentence acts as an interrogative particle. This differentiation in tone allows a speaker to create the (not entirely grammatical) sentence "ma1 ma1 ma4 ma3 de5 ma2 ma5?", or "Is Mother scolding the horse's hemp?" (Hanyu Pinyin: "Māmā mà mǎ de má ma?"; traditional characters: "媽媽罵馬的麻嗎?"; simplified characters: 妈妈骂马的麻吗?), where the series of "ma"s are differentiated in meaning only by their tone.

Tones can interact in complex ways through a process known as tone sandhi.

Tonal languages fall into two broad categories: register and contour systems. Mandarin and its close relatives have contour systems, where differences are made not based on absolute pitch, but on shifts in relative pitch in a word. Register systems are found in Bantu languages, which more typically seem to have 2 or 3 tones with specific relative pitches assigned to them, with a high tone and a low tone being the most common (plus a middle tone for languages that have a third pitch).

Please note that the word "pitch" is used loosely here, to refer to the comparative "difference" between a high pitch and a low pitch from one syllable to the next, rather than a contrast of absolute pitches such as one finds in music. As a result, when one combines tone with sentence contours, the musical pitch of a high tone at the beginning of a question may actually be lower than the musical pitch of a low-tone word at the end of the question, because the "average" pitch between the high and low tones rises (and falls) along with the overall pitch contour of the sentence.

Tone contours

A convenient notation attributed to the Chinese linguist Yuenren Chao splits pitch into five levels: 1, 2, 3, 4 and 5. The lowest pitch is 1, and the highest pitch 5. The variation in pitch can be described as a string of numbers, for instance for Mandarin

• Tone 1 /55/ high level tone
• Tone 2 /35/ mid rising tone
• Tone 3 /213/ low falling rising tone
• Tone 4 /51/ high falling tone

A mid-level tone would be indicated by /33/, a low level tone /11/, etc. These series of numbers are thus called "tone contours".

Tonal languages and music

It has been suggested that speakers of tonal languages are more likely to have absolute pitch than speakers of non-tonal languages. Speakers of Sino-Tibetan languages have been reported to speak a word in the same absolute pitch (within a quarter-tone) on various days. However, tone languages almost invariably use pitches relative to the speaker: in Doayo, for instance, the low tones of a female speaker can be the same absolute pitch as the high tones of a male speaker.

How the tones of syllables are handled when a song is sung in a tonal language depends on the language, as it is generally governed by the respective culture's traditions. In Mandarin pop music (but not in traditional theatre such as Beijing opera), the tones are generally dropped, thereby making the song hard to understand and sometimes ambiguous without written lyrics. In Cantonese (and Taiwanese), it is generally attempted to construct the melody or the lyrics in such a way that they fit to each other (even in modern pop). Other tonal languages may have other customs. (Vietnamese folk and classical music also respect tonal contours.)

See also

• Meeussen's rule
• Lion-Eating Poet in the Stone Den
• Tone name

de:Tonsprache fr:Langue à tons ko:성조 언어 ms:Bahasa berasaskan nada nl:Tonale taal pl:Język tonalny simple:Tone language fi:tooni