1. to do - to redo, to make - to remake, to write - to re-write, to sell - to resell, to mix - to remix, to paint - to repaint, to play - to replay, to view - to review, to mind - to remind, to call - to recall.
2. Happy - unhappy, fair - unfair, to cover - to uncover, like - dislike, lucky - unlucky, to lock - to unlock, to do - to undo, safe - unsafe, believable - unbelievable.