Yes, and can I assume that you had this on a listening exam? We need to know this so we can have it removed from the listening section as it causes confusion. And please when you write a comment please give more information. If you have anything further please let us know.
You see we have no idea what you were asked, which part of the exam it was nor what you answered, whether it was accepted or not. So, we need all that in order to be able to resolve the issue.
In addition, the bot doesn't know that there are two sentences that sound alike. When that happens we need to request that that sentence be omitted from the listening which I have done. It is the information given by the learner that makes it possible. Thanks for your help and please continue to give input.
I think you misunderstand the problem here. The program that grades the exercises has
"Αυτοί είναι γρήγοροι." as the correct answer
it does not have "Aυτή είναι γρήγορη."
In fact, "Αυτή είναι γρήγορη" does not exist on the course.
We have requested that "Αυτοί είναι γρήγοροι" be removed as a Listening Exercise so as to avoid any confusion. As I said we disabled this 3 years ago, but with the new audio it has been showing up again, so I disabled it again.
It may not have been accepted by the program yet.
However, there is no way...."Αυτή είναι γρήγορη." will ever be accepted. That sentence does not exist on the course so could not possibly be accepted.
If you happen to get this Listening again...(and I hope it is removed before that) then you can either
use the plural as shown above since that's the only one that exists on this course.
Or you can skip this Listening exercise.