Hm. Strange. Do you not say that some is "a" bishop in Portuguese?
We don't usually translate "a/an" when it is related to professions, unless you hae additional information (ele é um bispo italiano).
Valeu! I see you helping around here a lot, and it's awesome.
So, I get that one can leave the article out when talking about professions, but writing "O meu filho é um bispo" would be wrong?