二,虚拟语气
Ⅰ.条件状语从句中的虚拟语气
①.基本形式 if 从句主句
与现在相反过去时（were） would/could/should/might+ do 与过去相反过去完成时would/could/should/might+have
done
与将来相反 were to would/could/should/might+ do should/could
▲should也可以引导一个条件句,但所假设的事一般不会发生，且后面的主句（一般为祈使句）不能倒装。
②.倒装：如果条件句中的谓语动词含有were,should,had时，可以省
略if，把三个词放在主语之前构成倒装，如果句子是否定
句，not不跟着提前。
Eg. If he had come a little earlier, I might have met him.
Had he come a little earlier, I might have met him.
③.错综时间的虚拟条件状语
Eg. If I had studied hard, I would be in a very comfortable office now.
If you were older, I would have let you go yesterday.
④.含蓄的虚拟条件状语从句：无if从句的出现，用其他形式表示出
虚拟的意义，常见的词和词组：without, in the absence of,
Otherwise, but for, but
Eg. Without your help, I couldn't have done it well.
If there were no water, plants couldn't grow well.
He was held up in the traffic, otherwise, he wouldn't have been late If he hadn't been held up in the traffic, he couldn't have been late.
But for the rain, we would have a pleasant trip.
I could have written the paper before, but I was still.
II.其他状语从句中的定语从句
ⅰ.让步状语从句
在whethe r…or，though,no matter等引导的状语从句中，谓语经常用should/may+v.原，在这个句型中，可以将whether省略（or 不可省），though，no matter省略，再省略should和may，而把动词be放在主语前面，构成倒装
Eg. Everything around us, whether it may be/should be air, or water, or stone, is matter.
Everything around us, be it air or water, or stone, is matter.
Though he should/may be too weak to walk too much, I will advise him to walk a little every day.
a little every day.
ⅱ.在lest,in case,for fear that…引导的原因状语从句中，从句经常用should+v.原表示虚拟，其中in case可用陈述语气。
Eg. Here is some money in case you (should)need it.
The man escaped to another country for fear that he(should) be caught by the policeman.
She obeyed her husband in everything lest he(should)be angry.ⅲ.在so that/in order that引导的目的状语从句中，从句一般用could/should/might+v原
Eg. She stood away so that he could enter.
They went to the seaside in summer in order that they could enjoy their holiday together.
III.虚拟语气中的特殊情况
⒈ It is high/about time that+…(过去时) 是该做…
⒉would rather that+从句; as if/though如果后面用的是过去时，表示与现在或将来的事实相反，如果加的是过去完成时，表示与过去的事实相反，如果加的是过去完成时，表示与过去的事实相反。Eg.I would rather that you had not been so rude to her in the past.
I would rather you did nothing for the time being.
When a pencil is partly in a glass of water, it looks as if it were broken.
⒊believe ,think, except在否定句和疑问句中经常用虚拟语气来表示惊喜或疑惑。
eg. How can you believe that the new stadium should be so big?
I never except that he should know so much about it? IV.名词性从句中的虚拟语气
名词性从句中包括主语,宾语,表语和同位语从句
ⅰ.宾语从句：I suggest/request/demand/order/insist/recommend/ propose/require/desire that…
ⅱ.主语从句中的虚拟语气
a.It is suggested that…
b.It is important/essential/necessary/urgent/possible/
strange that(should)do
Eg. It is essential that we should work hard.
c. It is a must/a pity/a shame that…should +v.原
Eg. It is a must that we should finish the work in 2 days
It is a pity that we should have finished the simple work in 2 days. ⅲ.表语从句：My suggestion is that we (should)go at once.
ⅳ.同位语从句：The professor gave orders that the test should be
finished before half past ten.
