Why is "A optzecea e al meu" not accepted?
Because a optzecea is feminine but al meu is masculine - you cannot mix the genders. It must be either:
al optzecilea e al meu (masculine)
a optzecea e a mea (feminine)
My question is again about Daniel :-) who "il are pe al unsorezecelea" Why here is acsepted to say a optzecea e a mea and not asked for "o" or "pe".
Il are pe al unsprezecelea=He has the eleventh
A optzecea e a mea=The 80th is mine.
It's a simple but strange rule, and unfortunately, I simply don't have the time right now to explain it, if I can I will swing by later...