Cornēliō, virō magnae sapientiae, dabō pulchrum librum novum is rendered into English as "To Cornelius, a man of great wisdom, I will give this fine new book" on this page of Latin translation flashcards.
Everything is clear in this translation of the Latin sentence except for the noun virō. In Latin, vir is used here in the Dative case, virō, to be in keeping with the Dative form of Cornēlius, which is Cornēliō, presumably because of the apposition required by dābō.
If so, why is virō rendered into English in the Nominative case, as "a man"? Shouldn't it have been "To Cornelius, to a man [...]"?