St. Patrick was born in Britain and was a Christian missionary to Ireland which at the time was largely pagan. He was from a romanized Briton (Celtic) background ethnically and was born in Britain,...
If you are speaking to one person, you would say: Lá Fhéile Pádraig Sona Duit (law 'leh pawdrig sonna ditch) If you are speaking to several people, you would say: Lá Fhéile Pádraig Sona Dhaoibh...