ABSTRACT
Changes in pronunciation often occur when words are combined into phrases and sentences. The main cause of such change is speed of utterance: the organs of speech, passing from one position to another quickly, are apt to take short cuts, such short cuts often involving an alteration in articulation. This often leads to the substitution of another sound for one of the original sounds, or to the dropping out of a sound. In the course of the historical development of a language it is found that words change in pronunciation: these changes are due to more than one factor, but one of the main causes is known as assimilation. Many examples of historical and juxtaposition assimilation can be found in African languages. Also vowel harmony, a principle which rules that the vowels of neighbouring syllables shall have similarity with each other in also discussed in this chapter.
