Multi-Translation Layout:
18 Therefore He has mercy on whom He wills, and whom He wills He hardens.
18 So then he has mercy on whomever he chooses, and he hardens the heart of whomever he chooses.
18 Therefore God has mercy on whom he wants to have mercy, and he hardens whom he wants to harden.
18 All we're saying is that God has the first word, initiating the action in which we play our part for good or ill.