虚拟语气的详细用法是与现在事实相反、与过去事实相反、与将来事实相反三种用法，只需要理解之后进行相关的应用即可。具体的 操作如下：
1、虚拟条件句的三种基本类型：与现在事实相反、与过去事实相反、与将来事实相反。
2、与现在事实相反，条件从句的谓语用过去式，主句谓语用should（would,could,might）+动词原形。
3、与过去事实相反，条件从句的谓语用过去完成时（had+过去分词），主句谓语用should（would,could,might）+have+过去分词。
4、与将来事实相反，条件从句的谓语用过去式（be通常用were），主句谓语用should（would,could,might）+动词原形。
注意事项：
1、书写英语单词的时候一定要认真书写，防止有的字母之间混淆错误。
2、学习虚拟语气的详细用法时可以理解记忆，切不可盲目死记硬背，这样会得不到好效果。
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第1个回答 2017-08-14
一、虚拟语气的使用范围：
虚拟语气用来表示说话人所说的话并不是事实，而是一种假设、愿望、怀疑或推测。该语法主要用于if 条件状语从句中，也可用于主语从句、表语从句和宾语从句等。
二、虚拟语气的判断：
1. if 条件状语从句中虚拟语气的判断。if 条件状语从句有真实条件句和非真实条件句。假设条件可以实现的句子为真实条件句，反之为非真实条件句，要用虚拟语气。其形式分为以下三种：
(1) 与过去事实相反的假设。结构为：从句的谓语动词用“had + 过去分词”，主句用“should (would, could, might) + have + 过去分词”。例如：
If it had not rained so hard yesterday, we could have played tennis. 如果昨天没有下大雨，我们就能玩网球了。
(2) 与现在事实相反的假设。结构为：从句的谓语动词用过去式，系动词用were，主句的谓语用“should (would, could, might) + 动词原形”。例如：
If I were in your position, I would marry her. 如果我是你，我就娶她为妻。
(3) 与将来事实相反的假设。结构为：从句的谓语动词用“should (were to) + 动词原形”，主句用“should
(would, could, might) + 动词原形”。 例如：
If you should miss the chance, you would feel sorry for it. 如果你错过了这次机会，你会难过的。
2. 宾语从句中的虚拟语气。
(1) wish后接宾语从句中的虚拟语气：根据从句的意义来判断。
A: 表示与现在和将来事实相反的愿望，从句谓语动词用过去时态。例如：
I wish they were not so late. 要是他们来得不是这么晚就好了。
B: 表示与过去事实相反的愿望，从句谓语动词用过去完成时态。例如：
I wished he hadn't done that. 我真希望那件事不是他做的。
(2) 表示“要求、建议、命令”等动词后面的宾语从句中的虚拟语气。用于此结构的动词有：advise, direct, agree, ask, demand, decide, desire, insist, order, prefer, propose, request, suggest等。从句的谓语动词用“should + 动词原形”，其中should 可以省去。例如：
I insisted that he (should) go with us. 我坚持让他和我们一起去。
注意：当insist 表示“坚持认为”、suggest表示“表明，显示”时，不用虚拟语气。例如：
He insisted that she was honest. 他坚持认为她是诚实的。
3. 主语从句中的虚拟语气。
(1) It be + 形容词 + that... (should)...。用于该句型的形容词有：necessary, good, important, right, wrong, better, natural, proper, funny, strange, surprising等。例如：
It's natural that he should feel hurt. 他感到疼是很正常的。
(2) It be + 过去分词 ＋ that... (should)...。用于该结构中的过去分词是表示“建议、请求、命令”等词的过去分词。如： desired, suggested, requested, ordered, proposed等。例如：
It is desired that the building of the house be completed next month. 真希望这所房子在下个月前就能竣工。
(3) It is time (about time / high time) that... + (过去时或should + 动词原形)...。例如：
It is high time I went home now. = It is high time I should go home. 我该回家了。
(4) 表语从句、同位语从句中的虚拟语气。在suggestion, proposal, order, plan, idea, advice, decision等需要具体内容解释的名词后要使用虚拟语气，其谓语动词为：should + 动词原形，连接从句的that不能省略。例如：
My suggestion is that we should go there at once. 我的建议是我们应该马上去那儿。
4． 省略形式。有时可以把含有助动词、情态动词、be或have的虚拟条件句中的连词if 省去，而将had, should, were 等词提到主语之前，即用倒装结构。这时，如果出现not等否定词时需放在主语后面。例如：
If she had been here five minutes earlier she would have seen her old friend. → Had she been here five minutes earlier she would have seen her old friend. 如果她早到五分钟，她就会看见她的老朋友了。
虚拟语气用来表示说话人所说的话并不是事实，而是一种假设、愿望、怀疑或推测。该语法主要用于if 条件状语从句中，也可用于主语从句、表语从句和宾语从句等。
二、虚拟语气的判断：
1. if 条件状语从句中虚拟语气的判断。if 条件状语从句有真实条件句和非真实条件句。假设条件可以实现的句子为真实条件句，反之为非真实条件句，要用虚拟语气。其形式分为以下三种：
(1) 与过去事实相反的假设。结构为：从句的谓语动词用“had + 过去分词”，主句用“should (would, could, might) + have + 过去分词”。例如：
If it had not rained so hard yesterday, we could have played tennis. 如果昨天没有下大雨，我们就能玩网球了。
(2) 与现在事实相反的假设。结构为：从句的谓语动词用过去式，系动词用were，主句的谓语用“should (would, could, might) + 动词原形”。例如：
If I were in your position, I would marry her. 如果我是你，我就娶她为妻。
(3) 与将来事实相反的假设。结构为：从句的谓语动词用“should (were to) + 动词原形”，主句用“should
(would, could, might) + 动词原形”。 例如：
If you should miss the chance, you would feel sorry for it. 如果你错过了这次机会，你会难过的。
2. 宾语从句中的虚拟语气。
(1) wish后接宾语从句中的虚拟语气：根据从句的意义来判断。
A: 表示与现在和将来事实相反的愿望，从句谓语动词用过去时态。例如：
I wish they were not so late. 要是他们来得不是这么晚就好了。
B: 表示与过去事实相反的愿望，从句谓语动词用过去完成时态。例如：
I wished he hadn't done that. 我真希望那件事不是他做的。
(2) 表示“要求、建议、命令”等动词后面的宾语从句中的虚拟语气。用于此结构的动词有：advise, direct, agree, ask, demand, decide, desire, insist, order, prefer, propose, request, suggest等。从句的谓语动词用“should + 动词原形”，其中should 可以省去。例如：
I insisted that he (should) go with us. 我坚持让他和我们一起去。
注意：当insist 表示“坚持认为”、suggest表示“表明，显示”时，不用虚拟语气。例如：
He insisted that she was honest. 他坚持认为她是诚实的。
3. 主语从句中的虚拟语气。
(1) It be + 形容词 + that... (should)...。用于该句型的形容词有：necessary, good, important, right, wrong, better, natural, proper, funny, strange, surprising等。例如：
It's natural that he should feel hurt. 他感到疼是很正常的。
(2) It be + 过去分词 ＋ that... (should)...。用于该结构中的过去分词是表示“建议、请求、命令”等词的过去分词。如： desired, suggested, requested, ordered, proposed等。例如：
It is desired that the building of the house be completed next month. 真希望这所房子在下个月前就能竣工。
(3) It is time (about time / high time) that... + (过去时或should + 动词原形)...。例如：
It is high time I went home now. = It is high time I should go home. 我该回家了。
(4) 表语从句、同位语从句中的虚拟语气。在suggestion, proposal, order, plan, idea, advice, decision等需要具体内容解释的名词后要使用虚拟语气，其谓语动词为：should + 动词原形，连接从句的that不能省略。例如：
My suggestion is that we should go there at once. 我的建议是我们应该马上去那儿。
4． 省略形式。有时可以把含有助动词、情态动词、be或have的虚拟条件句中的连词if 省去，而将had, should, were 等词提到主语之前，即用倒装结构。这时，如果出现not等否定词时需放在主语后面。例如：
If she had been here five minutes earlier she would have seen her old friend. → Had she been here five minutes earlier she would have seen her old friend. 如果她早到五分钟，她就会看见她的老朋友了。
第2个回答 2020-10-03
听老师之间的对话学习虚拟语气
第3个回答 2017-08-14
虚拟语气详解
在英文句子中,谓语动词的语气是用来表示说话人对所讲内容的态度、看法以及心情等. 英文句子中谓语动词的语气有三种：
A）直陈语气（The Indicative Mood）直陈语气用于直截了当地陈述事实、描述状态： He has published quite a number of essays this year .他今年已发表了好几篇论文.
B)
祁使语气（The Imperative Mood）祁使语气用于提出请求、命令、建议或是劝告等： Wait outside until you
are asked . 请在外面等候,请你进再进去. Let's just take a break, shall we ?
我们休息一会儿,好吗?
C) 虚拟语气（The Subjunctive
Mood）虚拟语气用于表示主观愿望和假设的虚拟情况.虚拟语气不太顾及事实的存在,它表现出说话人的主观因素比较多.所以说话人所讲的内容往往是与事实相反的；或是其实现的可能性微乎其微,甚至于没有实现的可能性.当然,有时为了使说话的语气客气、缓和、委婉,也使用虚拟语气.
例如：
I wish you were more careful .但愿你更细心一些.
If I had more money, I would buy a bigger apartment. 我要是有再多一点钱,我就买一套更大一些房子. Would you mind shutting the door ? 劳驾您把门关上.
用于非真实条件句中的虚拟语气 条件句分为两种：真实条件句和非真实条件句.
与现在事实相违背
If I had time, I would certainly join you in the tennis match. （事实是：我没有时间）我要是有时间肯定和你一起打这场网球比赛.
If I were you, I would put her suggestion into account.（事实是：我并不是你）我要是你,我会考虑她的建议的.
与过去事实相违背
If I hadn't been caught by something, I would have come to your party yesterday.(事实是：我昨天被某些事缠住了) 我昨天要不是被些事缠住了,我就会去参加你们的聚会了.
If he had taken my advice, he might not have made such a bad mistake. （事实是：他没有听我的建议）要是他听进了我的劝告就不会犯这么严重的错误了.
与未来事实相违背
If
I should have a chance to try it, I would do it in another way.
（假设的情况不大可能发生）要是我有机会试一试,我会用另一种方法做的. Even if they were to fail, they
wouldn't lose courage. （说话人不希望假设的情况发生）即使他们万一失败,他们也不会泄气.
熟悉并掌握好下面的基本句式：
条件从句 主句 与现在事实相违背 过去式（动词是BE用were） Should / would + 动词原形
与过去事实相违背 had + 过去分词 would / should + have +过去分词
与未来事实相违背 1) should + 动词原形 2) were + 动词不定式 3) 过去式（动词是BE也可以用were） would / Should + 动词原形
1. 省略If的几种情况
1）当条件状语从句的谓语部分含有had、should、或were时,就将这样的词had、should、或were搬到句首把句子写成倒装句而将连词if省略.
例如：
If you were the manager here, what would you do? Were you the manager here, what would you do? 你若是这里的经理,你会怎么办?
If
he should act like that again, he would be fired immediately. Should he
act like that again, he would be fired immediately. 要是他再那样做,他会被立即解雇的.
2) 由某些介词短语取代了if引导的条件状语从句.
例如：
Without air, there would be no life on the earth. 要是没有空气,地球上就不会有生命了.
But for your help, the little boy would have been drowned. 要是没有你们的帮助,那个小男孩早就淹死了.
We could have done the work better in that case. 要是那样的话,我们本可以把工作干得更好一些的.
3) 由上下文的交代而省略了if引导的条件状语从句.在这种情况下,上下文事实上就是一个表示违背事实的条件句.上下文如果是由一个句子介绍的,那么这个取代了if条件状语从句的句子应该用直陈语气；而起主句作用的句子则要用虚拟语气.
例如：
He
would have come to see you earlier but he just came back from his
business trip .（本句中的上下文是：but he just came back from his business
trip,表示：要是他在家没出差的话）他本来早就来看你了,可他却出差刚刚回来.
But that you helped me, I would have failed in the experiment. （本句中的上下文是：But that you helped me,表示：要不是有你帮助我）要没有你帮助我,我的试验本做不成功的.
2. 虚拟语气用于某些从句中的情况：
1）在主语从句中在It + be +形容词/ 名词 + that从句的结构中,由于某些形容词/ 名词的原因,that从句中的谓语动词要用虚拟式"should + 动词原形"或是"动词原形".
这类形容词/
名词常见的有：essential（绝对必要的）, important（重要的）, advisable（明智的）,
desirable（希望能够的）, imperative（必须的）, natural（自然的）, necessary必要的）,
regretful（遗憾的）, strange（奇怪的）, proper（适当的）, urgent（紧急的）, duty（义务、责任）, a
pity（遗憾）, no wonder（难怪）, a regret（遗憾）,
例如： 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.
It is necessary that he be sent to Beijing right away. 有必要立即派他去北京.
另外,下列结构中主语从句的谓语动词也要求用虚拟语气：
It
is ordered that …(根据命令、要求……) , It is proposed that …(人们建议……) It is
desired that … (最好、需要……) , It is requested that … (人们要求……) It is
suggested that … (有人建议……) , It is recommended that …(有人推荐……) It is
demanded that …(根据要求……) , It is decided that …(已经决定……) It is arranged
that … (已经安排……) 等等.
例如：
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. 有人建议,英语晚会周六举行.
2)在宾语从句中某些动词后面,宾语从句的谓语要求用虚拟式.宾语从句中的谓语动词要用虚拟式"should + 动词原形"或是"动词原形".
这类要求宾语从句的谓语用虚拟式的动词,常见的有：
command（命令）, demand（要求）, desire（希望）, insist（坚持）, order（命令）,
propose（提议）, recommend（推荐）, request（要求）, require（要求）, suggest（建议）,等.
例如：
He proposed that we ( should ) set a dead line for the complement of the plan . 他提议拟定一个执行计划的期限.
They requested that we ( should ) send a delegation to their country. 他们请求我们派一个代表团到他们国家去.
I suggested that he ( should ) set off for our headquarters straightaway . 我建议他马上动身去我们的总部.
另外,wish和would rather / sooner that …后面的宾语从句,其中谓语动词的形式和对应用法如下表所述：
谓语动词的形式用法
过去式-------表示当时未能实现的愿望、意愿
过去完成式---表示过去未能实现的愿望、意愿
过去未来式---表示未来不大可能实现的愿望,意愿 （注意下列例句：wish自身的时态并不影响从句谓语动词的形式.）
I wish that I knew something about programming. 我希望我懂一点程序设计就好了.
I wished that I knew something about programming. 我当时希望我懂一点程序设计就好了. They wish that they hadn't said it to us. 他们希望他们没有对我们说过那件事.
They wished that they hadn't said it to us. 他们当时希望他们没有对我们说过那件事. I wish that you would get younger and younger .但愿你越来越年轻.
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.
He would sooner that he hadn't born until ten years ago .他宁愿他十年以前才出身.
3) 在表语从句和同位语从句中下面这些名词的后面所接的表语从句和同位语从句中,谓语动词要用虚拟式"should + 动词原形"或是直接用"动词原形" ：
idea（想法）, suggestion（建议）, motion（动议）, proposal（提议）, order（命令）, recommendation（推荐）,advice (建议) , instruction (指示、指令)等等.
例如：
The instruction was that nobody be allowed to go to sleep until further orders.（表语从句）指示要求,任何人不得在接到进一步的命令之前去睡觉.
My suggestion is that he leave for London at once . （表语从句）我的建议是他立即动身去伦敦.
What do you think of his proposal that we ( should )put on a play at the English evening? （同位语从句）他建议我们在英语晚会上演一个剧,你觉得怎么样?
4) 在状语从句中在某些状语从句中,要求谓语动词要用虚拟式"should + 动词原形"或是"动词原形".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.
例如： He took his umbrella with him lest it rain. （目的状语从句）他带了雨伞,以防下雨.
I'll keep a seat for you in case you should change your mind. （目的状语从句）我给你留个座,没准你会改变主意.
They burned all the important documents for fear that they fall into the enemy's hands. （目的状语从句）他们将所有的重要文件都烧毁了,以免它们落于敌人之手.
Though
everyone desert you, we will not .（让步状语从句,这是间或的用法.）即使所有的人抛弃了你,我们也不会. As
long as a volume hold together, We don't care much about its outer
appearance .（条件状语从句,这是间或的用法.）只要一本书不拆开,外表怎么样我们并不太在意.
This, if the news be true, will mean a lot to us. （条件状语从句,这是间或的用法.）如果这消息是真的,那对我们来说就太重要了.
I can still remember the whole thing in great detail as though it were yesterday.（方式状语从句）这一切我记忆犹新,仿佛就是昨天发生的事一样.
They are talking as if they had been friends for years. （方式状语从句）他们谈话的那股亲热劲就如同是多年的老朋友似的.
5) 在It is (high) time that…从句中在这个句型中的that…从句里,无论何时、何人称,其谓语动词都用"过去式".
这个句型表达的意思是"该是……的时候了".
例如：
It is time that we got ready for the final examination.该是我们为期末考试作准备的时候了. 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.
6) 在If only…从句中 "If only…从句"表示一种愿望或是向往的假设,其意义是"要是……就好了"、"但愿……".
这个句型中的语序是正常语序,不倒装.另外,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.
例如：
If only she could understand my real feelings. 要是她能了解我的真实想法就好了.
If only my mother had survived the disease and lived till now. 要是我妈妈没有死于疾病而活到现在就好了.
If only he would fine a satisfactory job after his graduation. 但愿他毕业后找到一份称心如意的工作.
3.
虚拟语气用于其他情况
首先,虚拟语气常用于表示客气、委婉的说法.它之所以能表示客气、委婉的意思,就是因为它的语气是虚拟的；也就是说,讲话的人有意识地将其所说的内容虚拟化,从而给听话人在是否接受所听到的内容方面留有较大空间、余地；而至于使听话人在是否接受所听到的内容方面感到有压力或是强迫感.从这个意义上讲,虚拟语气比直陈语气,祈使语气更为客气、委婉、礼貌.
例如： Could you tell me the way to the nearest shopping center ? 你能告诉我去最近的购物中心的路吗?
Would you mind lowering your voice? 请你小声点儿,行吗?
Perhaps you could get better results this way .你这样做效果或许要好一点.
Which seat might I take? 我可以坐哪个位子?
其次,在一些公式化的句子里也常用虚拟语气.这些公式化句子的谓语常用两种句式,即："动词原形"或是"may + 动词原形"(后者常用倒装句式).
例如：
God bless you! 上帝保佑你!
So be it then! 那就这样吧!
May the friendship between our two peoples last forever.祝愿我们两国人民的友谊万古青.
Come what may, we'll solve the problem by ourselves.无论发生什么情况,我们都要自己解决这个问题.
4.错综时间非真实条件句中的虚拟语气在非真实条件句中,我们在条件句和主句中所用的虚拟语气句式是相对程式化的.
If the boy hadn't been saved this afternoon, his family would not be in peace now . 如果那个男孩今天下午没有被救,他的家现在就不会如此安宁.
If the machine were in good conditions, we would have used it in our last experiment. 要是这台机器情况良好,我们上次就将它用于试验了.
If
you were to visit Hainan in two days, I could arrange some of my
friends there to meet you at the airport.
假如你过两天去海南,我现在就可以安排我在那儿的朋友去机场接你.本回答被提问者采纳
在英文句子中,谓语动词的语气是用来表示说话人对所讲内容的态度、看法以及心情等. 英文句子中谓语动词的语气有三种：
A）直陈语气（The Indicative Mood）直陈语气用于直截了当地陈述事实、描述状态： He has published quite a number of essays this year .他今年已发表了好几篇论文.
B)
祁使语气（The Imperative Mood）祁使语气用于提出请求、命令、建议或是劝告等： Wait outside until you
are asked . 请在外面等候,请你进再进去. Let's just take a break, shall we ?
我们休息一会儿,好吗?
C) 虚拟语气（The Subjunctive
Mood）虚拟语气用于表示主观愿望和假设的虚拟情况.虚拟语气不太顾及事实的存在,它表现出说话人的主观因素比较多.所以说话人所讲的内容往往是与事实相反的；或是其实现的可能性微乎其微,甚至于没有实现的可能性.当然,有时为了使说话的语气客气、缓和、委婉,也使用虚拟语气.
例如：
I wish you were more careful .但愿你更细心一些.
If I had more money, I would buy a bigger apartment. 我要是有再多一点钱,我就买一套更大一些房子. Would you mind shutting the door ? 劳驾您把门关上.
用于非真实条件句中的虚拟语气 条件句分为两种：真实条件句和非真实条件句.
与现在事实相违背
If I had time, I would certainly join you in the tennis match. （事实是：我没有时间）我要是有时间肯定和你一起打这场网球比赛.
If I were you, I would put her suggestion into account.（事实是：我并不是你）我要是你,我会考虑她的建议的.
与过去事实相违背
If I hadn't been caught by something, I would have come to your party yesterday.(事实是：我昨天被某些事缠住了) 我昨天要不是被些事缠住了,我就会去参加你们的聚会了.
If he had taken my advice, he might not have made such a bad mistake. （事实是：他没有听我的建议）要是他听进了我的劝告就不会犯这么严重的错误了.
与未来事实相违背
If
I should have a chance to try it, I would do it in another way.
（假设的情况不大可能发生）要是我有机会试一试,我会用另一种方法做的. Even if they were to fail, they
wouldn't lose courage. （说话人不希望假设的情况发生）即使他们万一失败,他们也不会泄气.
熟悉并掌握好下面的基本句式：
条件从句 主句 与现在事实相违背 过去式（动词是BE用were） Should / would + 动词原形
与过去事实相违背 had + 过去分词 would / should + have +过去分词
与未来事实相违背 1) should + 动词原形 2) were + 动词不定式 3) 过去式（动词是BE也可以用were） would / Should + 动词原形
1. 省略If的几种情况
1）当条件状语从句的谓语部分含有had、should、或were时,就将这样的词had、should、或were搬到句首把句子写成倒装句而将连词if省略.
例如：
If you were the manager here, what would you do? Were you the manager here, what would you do? 你若是这里的经理,你会怎么办?
If
he should act like that again, he would be fired immediately. Should he
act like that again, he would be fired immediately. 要是他再那样做,他会被立即解雇的.
2) 由某些介词短语取代了if引导的条件状语从句.
例如：
Without air, there would be no life on the earth. 要是没有空气,地球上就不会有生命了.
But for your help, the little boy would have been drowned. 要是没有你们的帮助,那个小男孩早就淹死了.
We could have done the work better in that case. 要是那样的话,我们本可以把工作干得更好一些的.
3) 由上下文的交代而省略了if引导的条件状语从句.在这种情况下,上下文事实上就是一个表示违背事实的条件句.上下文如果是由一个句子介绍的,那么这个取代了if条件状语从句的句子应该用直陈语气；而起主句作用的句子则要用虚拟语气.
例如：
He
would have come to see you earlier but he just came back from his
business trip .（本句中的上下文是：but he just came back from his business
trip,表示：要是他在家没出差的话）他本来早就来看你了,可他却出差刚刚回来.
But that you helped me, I would have failed in the experiment. （本句中的上下文是：But that you helped me,表示：要不是有你帮助我）要没有你帮助我,我的试验本做不成功的.
2. 虚拟语气用于某些从句中的情况：
1）在主语从句中在It + be +形容词/ 名词 + that从句的结构中,由于某些形容词/ 名词的原因,that从句中的谓语动词要用虚拟式"should + 动词原形"或是"动词原形".
这类形容词/
名词常见的有：essential（绝对必要的）, important（重要的）, advisable（明智的）,
desirable（希望能够的）, imperative（必须的）, natural（自然的）, necessary必要的）,
regretful（遗憾的）, strange（奇怪的）, proper（适当的）, urgent（紧急的）, duty（义务、责任）, a
pity（遗憾）, no wonder（难怪）, a regret（遗憾）,
例如： 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.
It is necessary that he be sent to Beijing right away. 有必要立即派他去北京.
另外,下列结构中主语从句的谓语动词也要求用虚拟语气：
It
is ordered that …(根据命令、要求……) , It is proposed that …(人们建议……) It is
desired that … (最好、需要……) , It is requested that … (人们要求……) It is
suggested that … (有人建议……) , It is recommended that …(有人推荐……) It is
demanded that …(根据要求……) , It is decided that …(已经决定……) It is arranged
that … (已经安排……) 等等.
例如：
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. 有人建议,英语晚会周六举行.
2)在宾语从句中某些动词后面,宾语从句的谓语要求用虚拟式.宾语从句中的谓语动词要用虚拟式"should + 动词原形"或是"动词原形".
这类要求宾语从句的谓语用虚拟式的动词,常见的有：
command（命令）, demand（要求）, desire（希望）, insist（坚持）, order（命令）,
propose（提议）, recommend（推荐）, request（要求）, require（要求）, suggest（建议）,等.
例如：
He proposed that we ( should ) set a dead line for the complement of the plan . 他提议拟定一个执行计划的期限.
They requested that we ( should ) send a delegation to their country. 他们请求我们派一个代表团到他们国家去.
I suggested that he ( should ) set off for our headquarters straightaway . 我建议他马上动身去我们的总部.
另外,wish和would rather / sooner that …后面的宾语从句,其中谓语动词的形式和对应用法如下表所述：
谓语动词的形式用法
过去式-------表示当时未能实现的愿望、意愿
过去完成式---表示过去未能实现的愿望、意愿
过去未来式---表示未来不大可能实现的愿望,意愿 （注意下列例句：wish自身的时态并不影响从句谓语动词的形式.）
I wish that I knew something about programming. 我希望我懂一点程序设计就好了.
I wished that I knew something about programming. 我当时希望我懂一点程序设计就好了. They wish that they hadn't said it to us. 他们希望他们没有对我们说过那件事.
They wished that they hadn't said it to us. 他们当时希望他们没有对我们说过那件事. I wish that you would get younger and younger .但愿你越来越年轻.
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.
He would sooner that he hadn't born until ten years ago .他宁愿他十年以前才出身.
3) 在表语从句和同位语从句中下面这些名词的后面所接的表语从句和同位语从句中,谓语动词要用虚拟式"should + 动词原形"或是直接用"动词原形" ：
idea（想法）, suggestion（建议）, motion（动议）, proposal（提议）, order（命令）, recommendation（推荐）,advice (建议) , instruction (指示、指令)等等.
例如：
The instruction was that nobody be allowed to go to sleep until further orders.（表语从句）指示要求,任何人不得在接到进一步的命令之前去睡觉.
My suggestion is that he leave for London at once . （表语从句）我的建议是他立即动身去伦敦.
What do you think of his proposal that we ( should )put on a play at the English evening? （同位语从句）他建议我们在英语晚会上演一个剧,你觉得怎么样?
4) 在状语从句中在某些状语从句中,要求谓语动词要用虚拟式"should + 动词原形"或是"动词原形".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.
例如： He took his umbrella with him lest it rain. （目的状语从句）他带了雨伞,以防下雨.
I'll keep a seat for you in case you should change your mind. （目的状语从句）我给你留个座,没准你会改变主意.
They burned all the important documents for fear that they fall into the enemy's hands. （目的状语从句）他们将所有的重要文件都烧毁了,以免它们落于敌人之手.
Though
everyone desert you, we will not .（让步状语从句,这是间或的用法.）即使所有的人抛弃了你,我们也不会. As
long as a volume hold together, We don't care much about its outer
appearance .（条件状语从句,这是间或的用法.）只要一本书不拆开,外表怎么样我们并不太在意.
This, if the news be true, will mean a lot to us. （条件状语从句,这是间或的用法.）如果这消息是真的,那对我们来说就太重要了.
I can still remember the whole thing in great detail as though it were yesterday.（方式状语从句）这一切我记忆犹新,仿佛就是昨天发生的事一样.
They are talking as if they had been friends for years. （方式状语从句）他们谈话的那股亲热劲就如同是多年的老朋友似的.
5) 在It is (high) time that…从句中在这个句型中的that…从句里,无论何时、何人称,其谓语动词都用"过去式".
这个句型表达的意思是"该是……的时候了".
例如：
It is time that we got ready for the final examination.该是我们为期末考试作准备的时候了. 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.
6) 在If only…从句中 "If only…从句"表示一种愿望或是向往的假设,其意义是"要是……就好了"、"但愿……".
这个句型中的语序是正常语序,不倒装.另外,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.
例如：
If only she could understand my real feelings. 要是她能了解我的真实想法就好了.
If only my mother had survived the disease and lived till now. 要是我妈妈没有死于疾病而活到现在就好了.
If only he would fine a satisfactory job after his graduation. 但愿他毕业后找到一份称心如意的工作.
3.
虚拟语气用于其他情况
首先,虚拟语气常用于表示客气、委婉的说法.它之所以能表示客气、委婉的意思,就是因为它的语气是虚拟的；也就是说,讲话的人有意识地将其所说的内容虚拟化,从而给听话人在是否接受所听到的内容方面留有较大空间、余地；而至于使听话人在是否接受所听到的内容方面感到有压力或是强迫感.从这个意义上讲,虚拟语气比直陈语气,祈使语气更为客气、委婉、礼貌.
例如： Could you tell me the way to the nearest shopping center ? 你能告诉我去最近的购物中心的路吗?
Would you mind lowering your voice? 请你小声点儿,行吗?
Perhaps you could get better results this way .你这样做效果或许要好一点.
Which seat might I take? 我可以坐哪个位子?
其次,在一些公式化的句子里也常用虚拟语气.这些公式化句子的谓语常用两种句式,即："动词原形"或是"may + 动词原形"(后者常用倒装句式).
例如：
God bless you! 上帝保佑你!
So be it then! 那就这样吧!
May the friendship between our two peoples last forever.祝愿我们两国人民的友谊万古青.
Come what may, we'll solve the problem by ourselves.无论发生什么情况,我们都要自己解决这个问题.
4.错综时间非真实条件句中的虚拟语气在非真实条件句中,我们在条件句和主句中所用的虚拟语气句式是相对程式化的.
If the boy hadn't been saved this afternoon, his family would not be in peace now . 如果那个男孩今天下午没有被救,他的家现在就不会如此安宁.
If the machine were in good conditions, we would have used it in our last experiment. 要是这台机器情况良好,我们上次就将它用于试验了.
If
you were to visit Hainan in two days, I could arrange some of my
friends there to meet you at the airport.
假如你过两天去海南,我现在就可以安排我在那儿的朋友去机场接你.本回答被提问者采纳
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