"My pink hat."
Translation:Το ροζ καπέλο μου.
It may seem redundant to you, but not to a Greek :)
I see that you are level 25 in Italian; you should be used to this "article + possessive" construction from there as well (il mio cappello rosa).
Similarly, Greek uses a seemingly-redundant definite article with determiners, e.g. αυτό το σπίτι for "this house" -- literally, "this the house". But that's normal for Greeks (or, say, Hungarians).