had done would/should/could/might＋have done 　　If you had come earlier，you could/would have met the star.

　　如果你早点来，你就会见到那位明星了。

　　If he had seen you yesterday，he would have returned you your book.

　　如果他昨天见到你，他就会还给你书的。

　　3．与将来事实相反

条件从句 主句 did/should do/

were to do would/should/could/might＋动词原形 　　If his flight should be delayed/were to be delayed/were delayed，we would fail to meet him.

　　万一他的航班被延误了，我们就接不到他了。

　　If these icebergs should melt at the same time，we would drown.

　　如果这些冰山同时融化的话，我们就都淹死了。

　　[即时训练1]　用所给词的适当形式填空

　　①The waiter would serve you more quickly if you spoke (speak)to him more politely.

　　②Do you think he would lend (lend)me his computer if I asked (ask)him nicely?

　　③If they really wanted (want) to see the house now，I would have (have)to get the permission of the owner.

　　二、非真实(虚拟)条件句的倒装

　　if虚拟条件句中有were，had，should时，可把if省略，而把were，had，should放在主语前，构成倒装结构。

　　Were I you(If I were you)，I would take the job.

　　如果我是你，我就会做那份工作。

　　Had I had time(If I had had time)，I would have gone and helped him.

　　如果我有时间，我就会帮助他了。

　　Should he come(If he should come)，tell him to ring me up.

　　万一他来，告诉他给我打电话。

[名师点津]