一、错综时间的虚拟语气：主从句该用
什么时间的的假设就用什么时间的
Eg: If he had listened to me, he would not be in trouble now.
要是他当时听了的话，他现在就不会有什么麻烦了
Eg: If iI were you, I would have taken his advice then.
我要是你，我当时就该听他的建议了
二、含蓄条件句的虚拟语气：假设的情况不用条件句表示，而是隐含在上下文中，
由介词(without,with,but for"要不是")，或副词otherwise替代。
Eg:Without air we could live on the earth.
=If there were no air,we.....
But for the storm we would have been there in time
=If there hadn't been the storm,we....
三、虚拟语气在wish类从句中的应用：wish"希望";if only"要是"；as if/as though
现在 were/did ; 过去 had done ; 将来 would(could...) do
I wish I were as young as you.
If only you had come at that time.
She looks as if would cry.
四、虚拟语气在would rather/sooner"责备或愿望"结构中的应用：
主语+would rather/sooner+主语+【did/were(对现在/将来的假设)；had done(对过去假设)】
I'd rather you posted the letter right away.
I'd rather you had returned the book yesterday.
I would rather/sooner you came tomorrow.
五、虚拟语气在it is (about/hight) time that句型的应用 "早就该做什么了"
表示抱怨或批评：it is (about/hight) time that sb. should do/did
(It is time to do sth.这个句型中不需要用虚拟语气)
It is time that the government took action.
It is about time that he should do something instead of just talking.
六、用(should) do 表"建议, 请求, 命令"后加that从句(v.或n.都虚拟):
一坚持：insist
二命令：order,command
四建议：suggest,advise,propose,recommend
四要求：demand,request,require,ask
变成名词词性：suggestion,proposal,requirement,order,demand,decision,advice,
desire,idea, importance,instruction,necessity,motion,perference,
recommendation,resolution,request
The doctor suggested that he (should) try to lose his weight.
My suggestion is that he (should) do the exercise first.
七、主语从句中对虚拟语气 It is +adj/n/done+that引导的主语从句，用(should) do：
形容词: advisable, appropriate,desirable,essential,fundamental,imperative'命令的'
,improtant,necessary,proper,urgent,vital
名词:a pity,a shame,no wonder that"难怪"
过去分词:arranged,desired,requested,suggested,recommended,required,demanded
It is suggested that pupils (should) wear shcool uniforms.
八、其他：
1、whatever,whichever,whenever,whoever,whereever,however,no matter-wh等让步状语从句中，虚拟语气结构为:may do(现在与将来)/may have done(过去),主句不限
2、though,although引导让状从，从句虚拟结构:should do
3、lest,in case, for fear that"以防,万一,唯恐"，从句虚拟结构为:should do
4、had hoped "本来想要, 但愿" +宾从用would do表示虚拟
5、暗示虚拟语气表示“本计划/本打算/本想要...”
intended/meant/hoped/wished/planned
或was/were+不定式完成时式
或had intended/meant/planned/hoped/wished+不定式
I will be waiting for him no matter how late he may come.
Although/Though he should often be late, he is a good student.
I obeyed her lest she (should) be angry.
I will not make a noise for fear that i (should) disturb you.
I had hoped that I wouldn't bore you by talking about my children.
I intended to have called on you, but I was busy at that time.
