People who speak tone languages aren’t really different from everyone else. In using tone in everyday speech, they are not driven by fierce hostility towards vowels and consonants or a devilish wish to frustrate language learners. As a speaker of two tonal languages (Mandarin and Fuzhou Min), I can tell you as much. Through this blog post, I hope to provide preliminary answers to two questions: What is tone, and where does tone come from?

Tone, intonation and stress are all ways in which we fine-tune the pitch of our voice to express differences in meaning. Pitch is often conceptualised on a scale from “low” to “high”, and the ability to manipulate pitch allows us to signal a question with a rising pitch or indicate stress in words like “present”. Tone is most commonly defined as contrastive pitch for distinguishing morphemic units. With tone, you can contrast words with identical segments but distinct pitch patterns, through difference in either pitch height (High vs. Low) or shape (Level vs. Contour). In Mandarin Chinese, for example, almost every morpheme is associated with one of four tones, which have distinct pitch shapes. For tone language speakers, distinguishing words through tonal differences is as natural as doing so through difference in vowels and consonants. In the following sound file, you can observe how the sounds [ma] combine with tones in Mandarin to form morphemes with distinct meanings (“mother”, “hemp”, “horse” and “scold”, in this order).

Tone is a highly areal feature. Although an estimated 50 to 70 percent of all human languages are tonal, the vast majority of these are clustered in Sub-Saharan Africa, Asia-Pacific, and Central and North Americas. Tone languages also differ considerably amongst themselves, and such differences often seem to be driven by language genealogy. One salient divide is between the so-called register tone languages and contour tone languages, which are respectively the norm in Africa and East Asia. Roughly speaking, register tone systems are made up of tones with level pitch (e.g., Yoruba’s high, mid and low tones), while contour tone languages have more complex tonal shapes. Fuzhou Min, for example, has a contour tone characterised by rising-falling pitch. Take a listen below (the word means “two”).

In many African languages, entire morphemes can consist only in tones – these tones seem able to“float” without being permanently attached to segments. The definite article in Bambara is said to be an example of this. The word for “the” in Bambara is a floating low tone, which docks onto nouns and changes their pitch shapes. To exemplify, the word for “river” in Bambara is pronounced [bá] (the accute accent denotes a high tone) in isolation, but “the river” is rendered as [bâ] (circumflex denotes falling tone). Here, we can construe the falling tone as the combination of a high tone (from the noun) and a low tone (from the floating definite article). The discovery of floating tones played an important role in launching the theory known as Autosegmental Phonology, which continues to dominate the way we represent our objects of study in phonology. The 1970s; those were glorious days for tones.

A frequent question for me at college formals is why people would want to “do” tones. I get what they are coming from. After all, English and many other languages seem perfectly able to cope without tones. Even if people take a liking to tones, why the hell do some languages use monstrously large number of tones (some Cantonese varieties reportedly have 10 tones)? There has been a whole branch of tonology devoted to these questions under the banner of “tonogenesis”. This is what got me interested in tones, so allow me to indulge in an example.

The best known source of tones are voicing contrast in obstruents (stops like /b/ and fricatives like /s/). The story goes like this. When you produce an obstruent that’s voiced, say /b/, you tend to lower your larynx and draw your arytenoid cartilages together, allowing your vocal folds to vibrate (for a very close view of vocal fold vibration, see the video at the end of this paragraph). These movements often depress pitch on following vowels. As time goes by, your listeners may pick up on this lowering effect as a consistent correlate of voicing. Then one day, you wake up to find your voicing contrast has gone (language change is brutal, man). Your listeners panic – how are they supposed to deal with all these new homophones? In desperation, they turn to pitch as the key to distinguish pair of words, at which point we may say the language has become tonal. On this hypothesis, if English were to lose the contrast between /b/ and /p/, we’d expect words like “bet” to develop a low tone and “pet” to associate with high tones. The scenario I sketched above may seem far-fetched, but we have very good evidence that this exact process happened in Khmu in Northern Laos, among other languages.

This post has not touched on the more exciting (in my view, anyway) phenomenon of tone sandhi, which I hope to write about in my next contribution. Meanwhile, I have prepared three take-away messages:

  1. Tone language speakers are not crazies.
  2. Tone languages are concentrated but incredibly diverse.
  3. Tones are versatile, fun to study, and well worth (future) linguists’ time to look into.


Further reading

1. The best introduction to tone:

Yip, Moira. 2002. Tone. Cambridge: Cambridge University Press.

2. On tonogenesis and its manifestation in Kammu:

Hombert, Jean-Marie. 1975. Towards a theory of tonogenesis: an empirical, physiologically and perceptually based account of the development of tonal contrasts in languages. University of California, Berkeley Doctoral dissertation.

Svantesson, J. & David House. 2006. Tone production, tone perception and Kammu tonogenesis. Phonology 23(2). 309.

3. Bambara floating tone:

Clements, Nick & Kevin C. Ford. 1979. Kikuyu tone shift and its synchronic consequences. Linguistic Inquiry 10. 179–210.

4. Autosegmental Phonology

Goldsmith, John A. 1976. An overview of autosegmental phonology. Linguistic Analysis 2. 23–68.