The big hint is to look at the ending. That "o" means it's not a bantu verb and it doesn't have the "look" of a loanword from Arabic ... and besides, they generally end in any vowel other than "o". It doesn't work if the noun ends in "a" of course, but that's less common than "o" or "i".
No, of course not. I can relate. My brain stalls at times.
It doesn't help that it's not a sentence at all so you can't even grammatically expect one kind of word. This is almost as bad as "Sheikh and prayer beads" ... I mean ... at least they're kind of opposites, not just a random noun for a person and one for a thing.