I joined this forum because I have a lot of questions about the Zulu course! I've been trying to learn by myself for a while now, and it's so great to have help with putting together sentences and phrases.
Some of what's in the course surprises or confuses me, and I don't know what's because the course is in the beta stage or because there's so much I don't know about Zulu.
For example, why does the course insist on "you all" for "ni-"? I know it's plural but usually in English we just say "you". I'm always getting caught by this one. 
Or, why is "ekuseni" always "early in the morning"? Is it because it derives from "ukusa" which is specifically "dawn", or is it just because Duo hasn't been programmed for variations yet?
I also keep getting in trouble for trying to translate "hamba" as "go". Is there some nuance to when you can use it that way, or is it just another beta issue?