LOL. Duo said i wrote "Αυτοί είναι ανάμεσά μας" with a typo and suggested "Αυτοί είναι μεταξύ μας". Ι βelieve this is a bug, but here comes the question - are μεταξύ and ανάμεςα interchangeable?
Is the double accent mandatory or optional in this case - αυτοί είναι ανάνεσά μας? - since I don't think there could be ambiguity in meaning here. It's not like 'μας' here could be an indirect object can it?
It's not a matter of ambiguity, in any case (possesive or pronoun). The accent is there because in verbal speech, there is actually an accent. There is no ambiguity in "Το ποδήλατό μου" but the second accent mark is necessary, because that's how it is pronounced. ;)