Duolingo is very flawed
Duolingo is very flawed. "it doesn't" has been marked incorrect at times and at other times "it does not" has been marked incorrect? So many errors - since when does "movie" translate as "le cinema"... so frustrating...
Aren't we all flawed in one way or another?? :-)
If you give an answer that you find correct, but the system rejects, you can report the sentence as "My answer should be accepted" (or similar).
I've done that, and I've received emails saying "your sentence has been added" some time (weeks) later.
In this way, we can contribute to improvement instead of just complaining.