I assume you are referring to "orange" You have been asked to please tell us what kind of exercise it was...just describe it. For example translate the sentence from...Eng to Gr, or choose the right word, or make the sentence by choosing the write words or whatever it was.
That will help Duolingo pinpoint the problem.
It is most definitely allowed. I'm assuming you are referring to the alternative spelling of "άνδρας" which we always include.
So, if your sentence was not accepted there might have been an error. We moderators cannot see your sentence therefore before you posted your comment here you should have made a REPORT.
Here's how to report.
Go to the bottom of the exercise page where you'll see REPORT Click on that:
Then choose what you want to REPORT: (You'll see these to choose from.)
-The audio does not sound correct.
-The dictionary hints on hover are wrong or missing.
-The Greek sentence is unnatural or has an error.
-The "Correct solution" is unnatural or has an error.
-My answer should be accepted. This is the
one you should click on if your translation was not accepted. After choosing the REPORT you want to make you should post on the comment page.