is this the most common word for return? i've heard γυριζω and ξαναρχω but never this
Yes, it is. Γυρίζω is also used but has other meanings, too, and ξανάρχομαι means "come again".
What is the meaning of this sentence? She returns like "She returns home" or "She returns something to someone"?
On its own like that, it means that she returns to some place (could be home). If we say αυτή επιστρέφει το βιβλίο then it takes the meaning of returning the book to someone.
If a woman bought a house but wants to return it (if that makes sense haha), could I say Αυτή επιστρέφει το σπίτι?
In that case, how would I say "She is returning home"?
I'm not a native, so i am not sure, but i guess you could do it, and to say that she is returning home you would use σε, like: "Αυτή επιστρέφει στο σπίτι."
she gives back - why is that not accepted?
Is "She is returning" a correct translation? If not, why not? It was marked wrong — written Greek to English, free-form text, mobile (Android).
Oops, never mind. Stupid autocomplete screwup on my phone.
My answer is the same as you gave. Why do you say it is wrong?I wrote: She returns.