There are two ways to form a negative statement in Zulu: one is with a- the other is with -nga-. The a- form is used to make a negative statement eg he doesn't smoke.
Most negatives in the present tense begin with an extra a- and change the final vowel to -i eg:
The third person present negative for class 1, 1a nouns - replace initial u- with aka- eg akakwazi he doesn't know, umama akayini the lady she isn't ironing and uMatthew akayi Matthew isn't going
Passive verbs do not change the end vowel eg anganelisiwe I'm not satisfied, angizwa kahle I don't understand = hear well and akubhenywa lapha no smoking allowed here
This page- www.newt.clara.co.uk/isizulu/no.htm
5 August 2002