Actually, the site does teach English, for Portuguese speakers for instance. Don't take my word for it, but I'm guessing we (People doing Portuguese from English) share the same database as people doing English from Portuguese. And the English the site promises to teach to non-native speakers is American English, thus why it's only accepting American English into the program. The same reason why duolingo doesn't accept European Portuguese translations from native Portuguese Speakers learning English, because they promise to teach us Brazilian Portuguese. Do you get what I mean? Anyway, I'm not saying your English is incorrect, I'm just pointing out why things are probably the way they are right now.
I do think they must be using the same database for the two languages. Sometimes I just misspell something in English by accident and the site won't accept it, although it is clear that I got the meaning of the Portuguese sentence, which is actually the aim of the exercise. I'm sometimes astonished why they correct my English so meticulously when I'm learning Portuguese and not English. :) I just didn't know that they were teaching American English but now I understand why "have you got" wasn't accepted.
It's not so terrible in American English is it?
"You have a watch?" was counted wrong. However, depending on the context of the situation that this sentence is used in, couldn't it be right? I don't want to hit the report question button just in case, since I might be wrong in saying that I'm right. I'm not sure... reply only if you have a very good reason why it was counted as wrong OR why I'M wrong, since I have no clue. I don't want any clutter all over this comment, please. It gets annoying, and no offense intended. :) Thanks.
This sounds quite quaint nowadays. You may be interested in this breakdown of the different ways of saying something similar:
Thanks for the comment. It actually doesn't sound quaint in Ireland or the UK, regardless of what the author of that article says. "Gotten" is frowned upon over here (I'm in Ireland),as an american expression. We use both "have you", and "have you got" in normal everyday use over here. What does "got" actually add to the sentence? It's a redundant word really.
This is what I call the First Rule of Duolingo: even if your sentence is rejected, it doesn't mean it's wrong. :-)
The "Report a Problem" button is right next to the "Discuss sentence" button that you must have pressed to make your original comment. It usually brings up several options including a "My sentence should be accepted" option, but even if it doesn't you can always describe the problem in the text box provided. Don't forget to hit the "Submit" button.
This is a matter constantly moaned about by Duolingo students who are fed up with having their time wasted, they having with annoyance very often to put up with giving the accepted Duolingo answer in place of what they know to be correct and/or permissible. The alternative is simply to abandon the exercise! It all boils down to the "setters" of the exercise quite simply not mastering the English language, something not being a particularly inspiring quality in the operation of a language-teaching organisation!