"Nobody knows him."
Translation:Ніхто не знає його.
It's correct. I think the current word order was chosen to match the word order of the English sentence and to highlight the double negation "ніхто не ...," which is typical for Ukrainian and not typical for English.
The word order is utterly odd to my native Ukrainian ear. It is a possible construction , but the last one I would choose without any context. It seems to be a common problem in the Ukrainian segment of Duolingo. Smells like Google Translate, sorry.
Isn't this a double-negative? Translating to English it would literally say: "Nobody doesn't know him." The fact that nobody knows him is already saying there isn't anyone who can know him. Saying nobody doesn't know him, just means everyone knows him. LOL
Sorry, but is there something I'm missing here that makes this correct? In English, people say things like all the time as colloquial English, however, it would be incorrect English.