关于if的虚拟语气我记得高中的时候if的虚拟里面可以用的情态动词有很多啊,像would ,could might ,sh

关于if的虚拟语气
我记得高中的时候if的虚拟里面可以用的情态动词有很多啊,像would ,could might ,should 等等,为什么现在做四级的时候好像就谈到了would /should 到底怎么回事啊

有时你也可以选择用could或 might,但是如果是选择题的话肯定不能这些词都在选项里,那就又好几个答案了.没法选了.我做四级的时候就碰到过各种虚拟语气的题, 比如有的要倒装,有的前半句用虚拟、后半句用真实语气.这都要读懂题判断的、、、
下面是总结.你参考参考、
1. 虚拟语气在if条件状语从句中的用法
与现在事实相反：（从句谓语动词）动词的过去式(be用were而不用was)\x09
（主句谓语动词） should/ would /could/ might+动词原形
与过去事实相反：（从句谓语动词） had + 过去分词\x09
（主句谓语动词） should/ would/could/might + have+过去分词
与将来事实相反：（从句谓语动词）1.should+动词原形 2.动词过去式 3.were to+动词原形\x09 （主句谓语动词） should/ would/ could/ might +动词原形
2. Wish 引导的宾语从句
与现在事实相反 ：\x09过去时（were）
与过去事实相反 ：\x09had+过去分词
与将来事实相反 ： would/could/might+动词原形
eg. I wish I were a bird.
I wish he hadn‘t done that. (do)
I wish I would be rich in the future.
3. 表示要求,命令,建议的虚拟语气
Keys：1). insist 2). order, command
3). advise, suggest, and propose 4). demand, require, request, desire
这些动词后面的宾语从句要使用虚拟语气用法.即从句中的动词使用should + 动词原形,
或者省略should.直接家原形
eg. The doctor suggested that he (should) try to lose his weight.
He insisted that we (should) tell him the news.
虚拟语气(二)
the Subjunctive mood （假设语气）
1. 表语从句、同位语从句中的虚拟语气
在suggestion, proposal, order, plan, idea, advice, decision等需要有内涵的 名词后面的表语从句、同 位语从句中,要使用虚拟语气.其谓语动词应用：should＋原形动词.另外连接从句的that不能省略.
eg. My suggestion is that we should go there at once.
What do you think of his proposal that we should put on a play at the English evening?
2、 It’s necessary/strange/natural/ important/pity/no wonder/impossible + that Clause 从句中的动词要用虚拟, 即(should)+动词原形
eg. It is strange that he (should) say so. 他居然会这样说,真是奇怪.
It is a great pity that you (should) think so. 他居然会这样想,真是一件憾事.
It is natural that a bird (should) rest in trees. 鸟在树上安歇是很自然的.
3、 在It is/was suggested /ordered / demanded / proposed / etc. 结构中要使用虚拟语气
eg. It‘s requested that we （should） keep the stability of the society for the people’s
peaceful life.
It’s suggested that the plan be carried out.
It is ordered that all the troops (should) withdraw three miles away. 根据命令,所有
部队撤至三英哩以外.
It is arranged that he leave for Canada on Friday. 照安排,他星期五动身去加拿大.
It is suggested that the English evening be held on Saturday.
4. would rather 后的宾语从句.
eg. I would rather you could teach me again.
The manager would rather that his secretary went to the meeting instead of him .经理
宁愿他的秘书代替他去开会.
5. as if, as though引导的从句.
以as if 、as though（似乎,仿佛）引出的方式状语从,如果表示真实情况应该用直陈语
气；如果表示非真实情况则应该用虚拟语气, 其谓语动词的虚拟式与wish后面宾语从句中谓
语动词的虚拟式相同.
eg. The little boy knows so many things as if he was a man.
6. 由if only （要是……,那该多好啊!）引导的惊叹句.如：
If only I had passed the test !
比较if only与only if：
only if表示"只有"；if only则表示"如果……就好了".If only也可用于陈述语气. eg. I wake up only if the alarm clock rings. 只有闹钟响了,我才会醒.
If only the alarm clock had rung.　　　当时闹钟响了,就好了.
If only he comes early.　　　　　　　但愿他早点回来.
7. It is (high) time that
It is (high) time that 后面的从句谓语动词要用过去式或用should加动词原形,但should不可省略.
eg. It is time that the children went to bed.
It is high time that the children should go to bed.
It is high time that we had our lunch. 该是我们吃午饭的时候了.
It is time that he made up his mind. 该是他作出决定的时候了.