PHONOLOGY: In many, so-called tone languages, a difference in pitch is used to distinguish lexical items. In such languages tone is a distinctive feature. The most common opposition is that between a high and a low tone. But also three- or four-way tonal distinctions occur in languages. A high tone is usually indicated with an acute (té) and a low tone with a grave (tè). EXAMPLE: in Margi we find the following lexical items:
(i) shú 'tail' shù 'to dry up'Also we may find so-called contour tones, i.e. a high and a low tone realized on the same vowel. We distinguish between a rising tone (te) and a falling tone (tê). Contour-tones are often analysed as complex tones. See tone stability.