1. 与现在事实相反的虚拟： If + did / were + ..., ... would/ should/ could/ might + do （动词原形） If I were you, I would go abroad at once. (I am not you.) If he knew it now, he could help me. (He doesn't know it now.) 2. 与过去事实相反的虚拟： If + had done + ..., ... would (might) have done ... If I had known your telephone number yesterday, I would have phoned you. (I didn't know your telephone number.) If you had come here a little earlier just now, you might have met her. (You didn't come here earlier.) 3. 与将来事实相反的虚拟： (1) If + should + v., ... would + v. （可能性很小）（译作“万一”） If it should rain tomorrow, you could stay at home. If I should fail, what should Ido? (2) If + did / were to + v ..., would + v. （完全不可能） If the sun were to rise in the west, I would lend you the money. If you finished it in 3 minutes, I would give you my car.

评论：
Souler: 好[小姐姐]