"Clothes were not attractive"
Help. I'm stuck on this one. First, why the "ha" instead of "i" since this is a thing, I think of the noun class 12-13. But secondly, shouldn't the negative end in "i" rather than "a"? And finally, the infix "zi" seems to make it an objective. Is that because the causative verb has to have an object? Like, the clothes were not made attractive? Sorry this one has me stumped.
You're overthinking it. Hazi- is the negative prefix. All negative prefixes are formed by ha+positive prefix, except first, second and third singular (although third singular with a locative suffix also follows this convention, e.g. yupo hapa, "(s)he is here", becomes hayupo hapa, (s)he is not here).
Hazi- = negative subject prefix for plural N/N class (class 10) (positive is zi-)
-ku- = negative past tense marker
NO object prefix
-pendeza = verb stem
The negative only ends in -i- in the present tense. That's kind of the negative equivalent of -na.
Basically, when switching to the negative, in the basic tenses, two things happen:
(1) The subject marker is made negative by adding ha- to the beginning.
In class 1, there are the irregular forms:
ha- + ni- = si-
ha- + u- = hu- (although I have seen and heard hau- for this from Kenyan sources)
ha- + a- = ha-
All the rest are regular: hatu-, ham-, hawa-, hau-, hai-, hali-, haya-, haki-, havi-, hai-, hazi-, hau-, hau-, haku-, hapa-, haku-, ham(u)-
(2) The markers of the basic tenses change:
Present: the prefix -na- becomes the suffix -i (only on verbs with -a otherwise)
Past: -li- becomes -ku-
Perfect: -me- becomes -ja- (although -ku- is sometimes equivalent and -ja- is more like "has not yet")
Future: -ta stays as -ta- (although I've heard that in some dialects it can change to -to-, but I've only heard that from one source.)