Кто знает

1) If I wasn't too busy, I would go to the concert. If I hadn't been too busy, I would have gone to the concert.
2) If no one came to help, we would be obliged to do the work ourselves. If no one had come to help, we would have been obliged to do the work ourselves.
3) If you put on your glasses, you would see better. If you had put on your glasses, you would have seen better.
4) What would you do if we were late? What would you have done if we had been late?
5) Would you be angry if we didn't come? Would you have been angry if we hadn't come?
6) Would he be displeased if I didn't ring him up? Would he has been displeased if I hadn't rung him up?
7) They would all be surprised if I made such a mistake.They would all have been surprised if I had made such a mistake.
8) If he didn't come in time, would we have to wait for him? If he hadn't come in time, would we have had to wait for him?Советую заглянуть сюда. Ничего сложного: http://englishfull.ru/grammatika/uslovnie-predlozheniya.html "Волшебные слова" тоже не помешали бы ...