1. - 2. to 3.-________1. If he has a toothache, he'll go to the dentistIf he had a toothache, he would go to the dentistIf he had had a toothache, he would have gone to the dentist2. They will wait until he comes backThey would wait until he came backThey would have waited until he had come back3. I will give you the book if I find itI would give you a book if i found itI would have given you a book if i had found