Alphabet — Number of Letters

The Umbundu alphabet consists of twenty letters: Vowels (5): a, e, i, o, u Consonants (15): f, h, j, k, l, m, n, p, s, t, v, w, y, and two digraphs: ng, nj The letters b, c, d, g, q, r, x, z of the English alphabet do not occur as independent letters. The sounds they represent are expressed by combinations: b is written mb d is written nd g is written ng j is written nj (before a vowel) (Stover, Observations upon the Grammatical Structure of the Umbundu, 1885, §1)