"This is mine! Not yours!"
Translation:זה שלי! לא שלךָ!
You don't see the tips and notes in the app or on mobile view on your browser, you have to get them via desktop view on a browser, or get them from the wiki, like http://duolingo.wikia.com/wiki/Hebrew_Skill:Possessives_1
"Yours" could be translated שלך (shelkha), but that would be the singular rather than the plural form of "yours". In English, we don't have the distinction between plural "yours" and singular "yours" so the sentence could be translated either way depending upon the intended meaning. Also, I believe zot would be used if "this" was talking about a feminine noun.
If I hadn't started Memrise Duolingo Hebrew vocab course first I would have thought I was an idiot, I didn't realise the app wasn't fully set-up until I got through 8 skills. That's only due to already knowing the alef bet & Memrise. I can't imagine how many quit from this huge issue.
The Duolingo system has been having problems with both nikud and punctuation since the beginning - because of the right-to-left direction of Hebrew. That's why your correct answer was marked as typo (it doesn't recognize nikud well) and why the exclamation mark is in the wrong place. Just ignore it.
it sounds like something you COULD say, I don't know if it is proper. But to say that, you would need to have one long sentence, (and not two like in the question given.)
As soon as you split it into two sentences, what does the "aei-no" indicate? For it to be pointing to the "zehu", it needs to be one sentence.
Well, "yours" is the same for both masculine and feminine, so you couldn't have made a mistake if you wrote שלך. You must have made another mistake that you didn't notice.
Unless you wrote זאת instead of זה. That is a mistake, because masculine זה is the default demonstrative pronoun.