We mentioned three simple possibilities for the intonation used in pronouncing the one-word utterances 'yes' and 'no'. These were: level, fall and rise. It will often be necessary to use symbols to represent tones, and for this we will use marks placed before the syllable in the following way (phonemic transcription will not be used in these examples - words are given in spelling):

Level        _yes       _no

Falling      yes       o

Rising       /yes       /no

This simple system for tone transcription could be extended, if we wished, to cover a greater number of possibilities. For example, if it were important to distinguish between a high level and low level tone for English we could do it in this way:

High level         ¯yes          ¯no

Low level          _yes         _no

Although in English we do on occasions say ¯yes   or   ¯no and on other occasions _yes or _no, a speaker of English would be unlikely to say that the meaning of the words 'yes' and 'no' was different with the different tones; as will be seen below, we will not use the symbols for high and low versions of tones in the description of English intonation. But there are many languages in which the tone can determine the meaning of a word, and changing from one tone to another can completely change the meaning. For example, in Kono, a language of West Africa, we find the following (meanings given in brackets):

High level    ¯bEN ('uncle')          ¯buu      ('horn')

Low level     _bEN ('greedy')      _buu ('to be cross')

Similarly, while we can hear a difference between English _yes, /yes and yes, and between _no, /no and o, there is not a difference in meaning in such a clear-cut way as in Mandarin Chinese, where, for example, ¯ma means 'mother', /ma means 'hemp' and ma means 'scold'. Languages such as the above are called tone languages; although to most speakers of European languages they may seem strange and exotic, such languages are in fact spoken by a very large proportion of the world's population. In addition to the many dialects of Chinese, many other languages of South-East Asia (e.g. Thai, Vietnamese) are tone languages; so are very many African languages, particularly those of the South and West, and a considerable number of Native American languages. English, however, is not a tone language, and the function of tone is much more difficult to define than in a tone language.