1庇胂衷谑率迪喾吹男槟庥锲形式
If＋主语＋动词的过去式（be要用were）……, 主句主语＋would（或should, could, might）＋动词原形。例如:
If I were you, I would buy a car. 如果我是你, 我就买辆车。（注: 在第一人称中, 主句中的would也可用should）
2. 与过去事实相反的虚拟语气形式
If＋主语＋had＋过去分词……, 主句主语＋would（或should, could, might）＋have＋过去分词。例如:
①If my lawyer __________ here last Saturday, he __________ me from going. （MET’89）
A. had been; would have prevented B. had been; would prevent
C. were; would prevent D. were; would have prevented
此题的正确答案为A。
②I didn't see your sister at the meeting. If she __________, she would have met my brother. （NMET’94）
A. has come B. did come C. came D. had come
此题的正确答案为D。
3. 与将来事实相反的虚拟语气形式
If＋主语＋动词的过去式（或were to ＋动词原形, 或should ＋动词原形）……, 主句主语＋would（或should, could, might）＋动词原形。例如:
If it should rain tomorrow, what would we do? 如果明天下雨, 我们怎么办? （注: 从句中的should rain可以换成were to rain或rained）
二、虚拟语气的其它句型
1毙槟庥锲用在动词wish带的宾语从句中, 宾语从句的谓语动词形式为:
①谓语动词用过去式（be用were）表示现在的情况。例如:
I wish I didn't have a cold. 但愿我没有感冒。
②谓语动词用过去完成式表示过去的情况。例如:
I wish I __________ you yesterday.
A. seen B. did see C. had seen D. were to see
此题的正确答案为C。
③谓语动词用would（或could, might）＋动词原形表示将来的情况。例如:
I wish you could come tomorrow. 但愿你明天会来。
注: as if（＝as though）引导的从句和if only后面所跟的句子也要用虚拟语气, 其形式和动词 wish所带的宾语从句的形式相同。例如:
①When a pencil is partly in a glass of water, it looks as if it __________. （NMET’95）
A. breaks B. has broken C. were broken D. had been broken
此题的正确答案为C。
②If only I had followed his advice. 若是我听了他的劝告就好了。
2庇媒榇识逃铮╳ithout..., butfor... ）、副词（otherwise）表示某种假设的情况, 相当于if引导的虚拟条件句。例如:
Without electricity human life __________ quite different today. （MET’91）
A. is B. will be C. would have been D. would be
此题的正确答案为D。
3毙槟庥锲用在It ＋be ＋important（necessary, strange, natural）＋that clause句型中, that clause的谓语动词应为“（should ＋）动词原形”。例如:
It is necessary that he __________ to the hospital at once.
A. should send B. be sent C. would be sent D. sent
此题的正确答案为B。
4毙槟庥锲用在It ＋be ＋time ＋that clause句型中, that clause的谓语动词应为“动词的过去式（be用were）或should ＋动词原形”。例如:
It is time that he went（should go）to bed. 他睡觉的时间到了。
5. 虚拟语气用在order, ask, suggest（建议）, demand, request, insist（坚持要）等动词后面的宾语从句中, 宾语从句的谓语动词应为“（should ＋）动词原形”。例如:
He suggested that she __________ at once.
A. starts B. start C. should start D. started
此题的正确答案为B和C。
6. 虚拟语气用在advice, idea, order, plan, suggestion, demand, proposal等名词后面的表语从句或同位语从句中, 从句的谓语动词应为“（should ＋）动词原形”。例如:
①My suggestion is that you __________ the meeting next Sunday.
A. held B. would hold C. should hold D. could hold
此题的正确答案为C。
②The teacher gave orders that the work __________ before 4 o'clock.
A. finished B. be finished C. should be finished D. finish
此题的正确答案为B和C。
7. 虚拟语气用在It ＋be ＋suggested（ordered, demanded, requested... ）＋that clause句型中, that clause的谓语动词应为“（should ＋）动词原形”。例如:
It is suggested that we（should）start the work at once. 有人建议我们立即开始工作。
8. 虚拟语气用在would rather后面的从句中。用过去式（be用were）表示现在或将来的情况; 用过去完成式表示过去的情况。例如:
①I would rather you went next Sunday. 我愿你下星期天去。
② I would rather you hadn't done that. 我真希望你没做那件事。
