Were it to rain tomorrow, our picnic would be canceled.
Had it not been for the storm, we would have arrived in time.
Should the earth stop running, what would happen?
二. 错综时间条件句
有时条件从句的动作和主句动作发生的时间不一致，这时需要根据意思采用表示不同时间的动词形式来进行调整。
If she had taken the doctor’s advice, she might still be alive.
If I were you, I would have accepted their terms.
三．含蓄条件句
1.有时候假设的情况并不用条件从句表示出来，而是通过介词短语来表示。
如 Without air(If there were no air), there would be no living things.
But for your help (If it hadn’t been for your help), I couldn’t have done it.
2. 假设的条件通过上下文表现出来。
I would go abroad for further study but that I am poor.
I was ill that day. Otherwise I would have taken part in the party.
3. 表示虚拟语气的主句或从句有时可以省略，但其含义仍可以推知。
（1）省去条件从句 You could have washed your clothes yourself. （你本可以自己洗衣服的。）省去了If you had wanted to。（事实是：你自己没洗衣服，因为你不想洗。）
（2）省去主句（常用以表示愿望）If my grandmother were with me! (如果我的祖母和我在一起多好啊！)事实是：祖母已不在世。
四、虚拟语气在名词性从句中的应用
① “wish+宾语从句”表示不可能实现的愿望，汉语可译为“可惜……、悔不该……、但愿……”。表示现在不能实现的愿望，从句的谓语动词用过去式；
表示将来不可能实现的愿望用“would/could+动词原形”；
表示过去不可能实现的愿望时用“had+过去分词”。如：
I wish I were better-looking. 要是我长得再漂亮些就好了。
I wish I had met the film star just now. 我要是刚才遇到那位电影明星该多好啊！
I wish I would be a solider. 我想当一名军人。
【考例】
How I wish every family a large house with a beautiful garden! (上海 2002春)
A. has B. had
C. will have D. had had
【答案】B。
②在表示建议、要求、愿望、命令、坚持、想法(advise, command, demand, decide, desire, insist, order, prefer, propose, request, require, suggest)等动词后面的宾语从句，或这些动词的同源名词后面所跟的同位语从句或表语从句中，从句谓语用“should+动词原形”，其中在美国英语中，should常省略。如：
The young man insisted that I (should) go with his fellows. 这个年轻人坚持要我同他的同伴们一起去。
The doctor advised that he change his job. 医生建议他换工作。
【考例】Teachers recommend parents their children under 12 to ride bicycles to school for safety. (福建 2010)
A. not allow B. do not allow
C. mustn’t allow D. couldn’t allow