"The cat's men."
Translation:Fir an chait.
I don't know when these fill in the blank sentences became necessary but now I have found one that didn't accept the answer that it gave back as corrected.
Clarification - it is demanding capitalization for "Fir". Absolutely every exercise so far has ignored letter case as well as punctuation (except apostophe which can be critical).
That sounds like an issue with the functionality of whatever version of Duolingo you are using - take a screenshot that demonstrates the problem, and submit a bug report with the screenshot and a detailed description of the version of Duolingo that you are using (iphone app, android app, website, the web browser you use, etc). The people that are in a position to fix bugs in Duolingo don't read Sentence Discussions, and your comment in a sentence discussion will never be acted on.