"He is a modern man."
Translation:Αυτός είναι ένας σύγχρονος άντρας.
Is it wrong to write: "Είναι σύγχρονος άντρας"? I've picked up the habit of dropping the indefinite article in these types of sentences, but I'm not entirely sure when it's allowed and when it isn't.
Yes, it is perfectly right. With the idefinite it is just a little bit more emphatic.