Acholi phonology

Acholi has vowel harmony: all vowels in a word have to belong to a single class (e.g. the cold vs.  to separate). There are two sets of five vowels, distinguished by the feature [+/-ATR].

Acholi is a tonal language. Thus, some words may be distinguished by tone alone, e.g. bèl (low) 'wrinkled' vs. bél (high) 'corn' and kàl (low) 'place enclosed by a palisade' vs. kál (high) 'millet'. Tone furthermore plays a role in verb conjugation.

The above were the old work of the missionaries Alfered Malandra and Crazzolara published in 1955. However, a more up-to-date Acoli orthography by Janet Lakareber shows that a vowel in Acoli language has more than two pronunciations. A monosyllabic word in Acoli has 14 different pronunciations. This is explained in the nine books of Acoli Accented Orthography.