谁能够和我具体地说说英语语法中的虚拟语态吗?

谁能够和我具体地说说英语语法中的虚拟语态吗?

1．虚拟语气在条件句中的用法
（1）若表示与现在事实相反的假设,则条件从句中用过去式,主句中用过去将来式（would,should,could,might + 动词原形）；若表示某事将来实现的可能性不大,则条件从句中用should + 动词原形也可用“were to+动词原形”或用过去式动词.如：
J I would certainly go if I had time．（现在）
J If it should rain,we wouldn't go out.（将来）
J If I knew German,I would read the paper to you．（现在）
J If he were here,we could ask him．（现在）
（2）若表示与过去事实相反的假设,从句中用过去完成式,主句中用过去将来完成式（should,would,could,might + have + 过去分词）.如：
J If I had set off a little earlier,I would have caught the train．
J She would / might have come if she hadn't been so busy．
J If I hadn't taken your advice,I would have made a bad mistake．
J If only you hadn't told him the news．
（3）含有虚拟语气的条件状语从句中,如有had,should,were 这三个词的话,在正式或书面语言中可将if省略,再将句子的主语和谓语动词实行全部倒装或部分倒装.如：
J Had they time（=If they had time）,they would certainly come and help us．
J Should it be fine（=If it should be fine）,we would go for an outing．
J Were I go（=If I were you）,I would go．
（4）若主句从句所指的时间不一致,即条件从句表示与过去事实相反,主句表示与现在事实相反；或者条件从句表示与现在事实相反,主句表真实情况,则从句中应采用与具体时间相对应的虚拟形式.如：
J If it had rained last night（过去）,It would be very cold today（现在）．
J If I had taken your advice（过去）,I should have no trouble with the work now（现在）．
2．虚拟语气在宾语从句中的用法
在动词suggest,order,demand,propose,request,command,insist等后的宾语从句中,用虚拟语气（即Should+动词原形或只用动词原形）来表示愿望、建议、命令、请求等.在动词wish /would rather后的宾语从句中,用过去式表示与现在事实不符,用过去完成式表示与过去事实不符.如：
J I suggest that we（should）set off at once．
JThe doctor insisted that the patient (should)be X-rayed．
JI wish I were as strong as you．
J I would rather that you hadn't told him．
3．虚拟语气在主语从句中的用法
在It is necessary/important/strange/natural；It is requested/suggested/desired/proposed；it is a pity等结构后的主语从句中要用虚拟语气,即Should+动词原形或只用动词原形.如：
J It is necessary that he（should）be sent there at once．
JIt is requested that Professor Li（should）give us a speech．
JIt is desired that we（should）get everything ready by tonight．
4．虚拟语气在表语从句、同位语从句中的用法.
在 suggestion,proposal,idea,plan,order,advice等名词后的表语从句、同位语从句中要用虚拟语气,即should+动词原形或只用动词原形.如：
J Our suggestion is that you（ should）be the first to go．
J My advice is that we（should）send for Doctor Li．
J Do you know the order that you（should）keep watch?
5．虚拟语气在其他状语从句中的用法
在as if引导的状语从句中,用过去式表示与现在事实不符,用过去完成式表示与过去事实不符；在so that,in order that引导的状语从句中,常用should/would/could/might+动词原形来表示虚拟语气.如：
JThey talked as if they had been friends for years．
J She stayed at home for a few days so that she could take care of her mother．
J He took a taxi to the station so that she should not miss the train．
6．虚拟语气在定语从句中的用法：
在it is time后面的定语从句中常用过去式表示虚拟.
J It’s time I was going.
J It’s time somebody taught you to behave yourself.