I assume this was found on a listening exercise. Please give more information, otherwise, we have no way of knowing. If it were listening yes it would sound the same so we will have to delete it. The listening is not in the hands of the team and the bot doesn't know how words sound but chooses sentences at random. We've had this problem before and I'll try to get to the bottom of it.
I just had the same experience. It is a listening exercise with no clues. The audio is: Αυτοί / Αυτή είναι ανάμεσα μας. I didn't lose a heart or anything because I was doing it as a review, but I originally typed "Αυτή" instead of "Αυτοί". This was just to bring it to your attention.
As you can see from the comments above this sentence was disabled 3 years ago because of the confusion caused by there being other words that sound the same...homophones.
And there have been no comments until now. Why this suddenly came out we here do not know. Our job is to help with language-related issues.
Please use the Help channel to report it. see the bottom of this page for the link.
And be sure to give a lot more information. Where you encountered it? What the reply was, the corrected sentence etc.
Sentences with homophones should not appear in Listening exercises and there had been no problem for the past few years. However, it seems that with the new audio that's being tested the homophones have been reintroduced. We are disabling any we find.
Glad you were able to avoid a problem this time. We'll try to get all such sentences removed as soon as we can.
I'm afraid this is not the place to post this problem this forum is for language-related discussions. Of course, we have made the problem known to Duolingo and now we are waiting.
Please, report that on the exercise page.
Thank you for your help.
Another problem with this as a listening exercise. My Greek isn't good enough to get many of these words right away, so I listen to the slow version. Listening to the slow version for this, there seems to be an extra syllable at the beginning of "μας", so it sounds something like "ουμας." Reported.
It is also correct to write: [Αυτοί/Αυτές/Αυτά] είναι ανάμεσα μας. as well as " [Αυτοί/Αυτές/Αυτά] είναι μεταξί μας."
So, don't be in such a hurry to decide what can be forgotten.
Please see here to find the translations you need etc
TIPS TO MAKE LEARNING EASIER and EFFECTIVE + HOW TO REPORT A PROBLEM
And check out the Greek Forum here with more links.