Translation:Αυτός είναι ο καφές μου.
Shouldn't be αφτό?
Καφές is masculine therefore you need "αυτός"
Why "Αυτος καφές ειναι δικος μου" would be wrong?
You always need the article with nouns
If είναι καφές is acceptable (the previous question), why is the ο necessary here? Isn't the article implied by the είναι?