虚拟语气的用法

1、与现在事实相反：若与现在事实相反，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”。 2、与过去事实相反：若与过去事实相反，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”。 3、与将来事实相反：若与将来事实相反，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”。 扩展资料： 虚拟语气的应用条件： 在表示假想的虚假的、与事实相反的或难以实现的情况时用虚拟语气，表示主观愿望或某种强烈情感时，也用虚拟语气。即当一个人说话时欲强调其所说的话是基于自己的主观想法，愿望，假想，猜测，怀疑或建议，而不是根据客观实际，就用虚拟语气。主要是英语语法的一种表达。 条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设或实际可能性不大的甚至完全不可能发生的情况，故采用虚拟语气。 参考资料来源： 百度百科-虚拟语气

一、 条件句中的虚拟语气 1. 条件句中虚拟语气的形式 从句中提出一种与客观现实不相符或根本不可能存在的条件，主句会产生的一种不可能获得的结果。条件句中的虚拟语气根据不同的时间有三种不同的形式。 2. 条件句中的虚拟语气的举例 (1) 将来时的条件句中的虚拟语气。如： If he should go to Qing Hua University, he would make full use of his time. 如果他要上清华大学的话，他就会充分利用他的时间了。 If he were to come here, he would tell us about it. 如果他要来的话，他会通知我们一声。 (2) 现在时的条件句中的虚拟语气。如： If he were free, he would help us. 要是他有空的话，它会帮助我们的。 If he studied at this school, he would know you well. 如果他在这所学校学习的话，它会对你很熟悉。 (3) 过去时的条件句中的虚拟语气。如： If I had seen the film, I would have told you about it. 我如果看过这场电影，我会把电影内容告诉你了。 If I had got there earlier, I would have met Mr. Li. 如果我早点到那儿，我就会会到了李先生。 3. 运用条件句中的虚拟语气时，须注意的几个问题 (1) 当从句的主语为第三人称单数时，谓语动词若是系动词be时，可用 was 代替 were。但在倒装虚拟结构及 if I were you, as it were 中，只能用 were。如： Were I ten years younger, I would study abroad. 要是我还年轻十岁的话，我会去国外学习。 If I were you, I would try my best to grasp the chance. 要是我是你的话，我要尽力抓住这次机会。 (2) 有时，虚拟条件句中，主、从句的动作若不是同时发生时，须区别对待。 ①从句的动作与过去事实相反，而主句的动作与现在或现在正在发生的事实不符。如： If I had worked hard at school, I would be an engineer, too. 如果我在学校学习刻苦的话，我现在也会使工程师了 If they had informed us, we would not come here now. 如果他们通知过我们的话，我们现在就不会来这里了。 ②从句的动作与现在事实相反，而主句的动作与过去事实不符。如： If he were free today, we would have sent him to Beijing. 如果他今天有空的话，我们会已经派他去北京了。 If he knew her, he would have greeted her. 要是他认识她的话，他肯定会去问候她了。 ③从句的动作与过去发生的情况相反，而主句的动作与现在正在发生的情况相反。如： If it had not been raining too much, the crops would be growing much better. 如果天不下太多的雨的话，庄家会长得更好。 If he had been working hard, he would be working in the office now. 要是他工作一直努力的话，他现在已进了办公室了。 (3) 当虚拟条件句的谓语动词含有 were, should, had 时，if 可省略，而将 were, should, had等词置于句首。如： Should he agree to go there, we would send him there. 要是他答应去的话，我们就派他去。 Were she here, she would agree with us. 如果她在这儿的话，她会同意我们的。 Had he learnt about computers, we would have hired him to work here. 如果她懂一些电脑知识的话，我们会已经聘用他来这里工作了 (4) 有时，句子没有直接给出假设情况的条件，而须通过上下文或其他方式来判断。如： I would have come to see you, but I was too busy. 我本该来看你了，然而我太忙了。 But for his help, we would be working now. 要不是他的帮助，我们还会在工作呢。 Without your instruction, I would not have made such great progress. 要是没有你的指导，我不会取得如此大的进步。 (5) 有时，虚拟条件句中，主、从句可以省略其中的一个，来表示说话人的一种强烈的感情。 ①省略从句 He would have finished it. 他本该完成了。 You could have passed this exam. 你应该会通过这次考试了。 ②省略主句 If I were at home now. 要是我现在在家里该多好啊。 If only I had got it. 要是我得到它了该多好啊。 二、其他状语从句的虚拟语气 1. 目的状语从句中的虚拟语气 (1) 在 for fear that, in case, lest 引导的目的状语从句中，若用虚拟语气时，从句谓语为： should + 动词原形。并且 should 不能省略 She examined the door again for fear that a thief should come in. 她又把门检查了一遍，以防盗贼的进入。 He started out earlier lest he should be late. 他很早就出发了以防迟到。 (2) 在 so that, in order that 所引导的目的状语从句中，从句中的谓语为：can / may / could / might / will / would / should + 动词原形。如(from www.yygrammar.com)： He goes closer to the speaker so that he can hear him clearer. 他走近说话的人以便能挺得更清楚。 He read the letter carefully in order that he should not miss a word. 他把信读得很仔细以便不漏掉一个单词。 2. 让步状语从句中的虚拟语气 (1) 在 even if, even though 所引导的让步状语从句中，可用虚拟语气，主句、从句的结构与 if 所引导的条件从句结构相同。如： Even if he were here himself, he should not know what to do. 即使他亲自来也不知该怎么办。 Nobody could save him even though Hua Tuo should come here. 即使华佗在世也救不了他。 (2) 在whatever, whichever, whenever, whoever, wherever, however, no matter wh-word 等引导的让步状语从句中，从句虚拟语气结构为： ① may +动词原形(指现在或将来)。如： We will finish it on time no matter what / whatever may happen. 不管发生什么事，我们都要按时完成。 We will find him wherever / no matter where he may be. 无论他在哪里，我们都要找到他。 I will wait for him no matter how late he may come. 不管他来的多么晚，我都会等他。 ② may +完成式(指过去) ，主句结构不限。如： You mustn’t be proud whatever / no matter what great progress you may have made. 不管你取得了多么大的进步，你也不能骄傲(from www.yygrammar.com)。 We must respect him no matter what / whatever mistakes he may have made. 不管他翻过什么错误，我们必须尊敬他。 (3) 在though, although等引导的让步状语从句中，从句虚拟语气结构为 should +动词原形，主句结构不限。如： Although / Though he should often be late, he is a good student. 尽管他经常迟到，他还是个好学生。 Although / Though he should be secretary, he must obey the rules. 尽管他是书记，他也必须遵守规定。 3. 方式状语从句中的虚拟语气 as if, as though 引导的方式状语从句常用虚拟语气。虚拟语气的结构为下图所示。 例如： They began to talk warmly as if they had known each other for long. 他们开始热烈的谈论起来就好像他们已相互认识很久了。 He coughed twice as if someone should come. 他咳嗽两声就好像有人要来了。 4. 原因状语从句中的虚拟语气 amazed, angry, annoyed, astonished, disappointed, frightened, happy, pleased, proud, sorry, surprised, upset 等后面的状语从句中常用虚拟语气。其虚拟语气的结构为： ① should + 原形动词(指现在或将来)。如： He was angry that you should call him by name. 他很生气，你竟然对他直呼其名。 I was astonished that he should not answer such an easy question. 我很惊讶他竟答不出如此简单的问题。 ② should + 完成式, 指过去。如： I’m very sorry that you should have failed the exam. 我很遗憾，你这次考试竟然失败了。 I was very surprised that Father should have known what I did yesterday. 我很吃惊，父亲竟指导我昨天所作的事情

1、对现在假设的情况 从句:If+主语+动词一般过去时(Be动词用were) 主句:主语+ should/would/might/could+do； If I were you, I would take an umbrella. 如果我是你,我会带把伞。(事实:我不可能是你) If I knew his telephone number, I would tell you. 如果我知道他的电话号码,我就会告诉你。(事实:不知道) If there were no air or water, there would be no living things on the earth. 如果没有水和空气,地球上就不会有生物。(事实:地球上既有空气也有水) 2、对过去没做的事情的假设 实际还是没做 从句：If+主语+had+done 主句：主语+should/would/might/could+have done If I had got there earlier, I should/would have met her. 如果我早到那儿,我就会见到她。(事实:去晚了) If he had taken my advice, he would not have made such a mistake. 如果他听我的劝告的话,就不会犯这样的错误了。(事实:没有听我的话) 3、对过去没做的事情的假设 实际还是没做 从句: ①if+主语+were to do ②if+主语+should+do ③if+主语+动词一般过去式(be动词用were) 主句: 主语+should/would/might/could+do 例: If he should come here tomorrow, I would talk to him. 如果他明天来这儿的话,我就跟他谈谈。(事实:来的可能性很小,不可能) If there were a heavy snow next Sunday, we would go skating. 如果下周日下大雪,我们就去滑冰。(事实:下雪可能性很小,不可能) If she were to be here next Monday, I would tell her about the matter. 如果她下周一来这儿的话,我就会告诉她这件事的始末。(事实:来的可能性很小,不可能) 4、错综条件句 有时,虚拟条件句中, 如果主句和从句的谓语动作若不是同时发生时, 虚拟语气的形式应作相应的调整。这种条件句叫错综条件句。 ①从句的动作与过去事实相反,而主句的动作与正在发生的事实不符。 例: If I had worked hard at school,I would be an engineer now. 如果我当时在学校学习刻苦的话,我现在就是一个工程师了 If they had informed us,we would not come here now. 如果他们通知过我们的话,我们现在就不会来这里了。 ②从句的动作与现在事实相反,而主句的动作与过去事实不符。 例: If he were free today, we would have sent him to Beijing. 如果他今天有空的话,我们就已经派他去北京了。 If he knew her, he would have greeted her. 要是他认识她的话,他肯定会去问候她了。 扩展资料 应用条件： 在表示假想的虚假的、与事实相反的或难以实现的情况时用虚拟语气，表示主观愿望或某种强烈情感时，也用虚拟语气。即当一个人说话时欲强调其所说的话是基于自己的主观想法，愿望，假想，猜测，怀疑或建议，而不是根据客观实际，就用虚拟语气。主要是英语语法的一种表达。 参考资料来源：百度百科-虚拟语气

16. 虚拟语气

1） 概念
　　 虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，不一定是事实，或与事实相反。

2） 在条件句中的应用
　　 条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。



16.1 真实条件句

　　真实条件句用于陈述语气，假设的情况可能发生，其中 if 是如果的意思。
　
　　时态关系
句型： 条件从句　　　 主句
　　 一般现在时　　 shall/will + 动词原形
　if he comes, he will bring his violin.

典型例题
　the volleyball match will be put off if it ___.　
a.　will rain　 b. rains　 c. rained　 d. is rained
　答案b。真实条件句主句为将来时，从句用一般现在时。

注意：
1） 在真实条件句中，主句不能用be going to表示将来，该用shall, will.
　(错) if you leave now, you are never going to regret it.
　(对) if you leave now, you will never regret it.
　2） 表示真理时，主句谓语动词便不用shall (will) +动词原形，而直接用一般现在时的动词形式。



16.2 非真实条件句

1）时态：可以表示过去，现在和将来的情况。它的基本特点是时态退后。
a.　 同现在事实相反的假设。
句型 ： 条件从句　　　　　主句
　　　　一般过去时　　　should( would) +动词原形
　 if they were here, they would help you.

b.　 表示于过去事实相反的假设。
句型： 条件从句　　　　　 主句　　　　　
　　　过去完成时　　　 should(would) have+ 过去分词
　 if she had worked harder, she would have succeeded.　　
　 the rice would not have been burnt if you had been more careful.　
　 if my lawyer had been here last saturday, he would have prevented me from going.

　 if he had come yesterday, i should / would have told him about it.
　 含义：he did not come yesterday, so i did not tell him about it.
　 if he had not been ill and missed many classes, he would have made greater progress.
　 含义： he was ill and missed many lessons, so he did not make greater progress.　

c.　 表示对将来的假想
　句型：　 条件从句　　　　　　 主句
　　　　 一般过去时　　　　　 should+ 动词原形
　　　　 were+ 不定式　　　　 would + 动词原形
　　　　 should+ 动词原形
　if you succeeded, everything would be all right.
　if you should succeed, everything would be all right.
　if you were to succeed, everything would be all right.
　


16.3 混合条件句

　 主句与从句的动作发生在不同的时间，这时主，从句谓语动词的虚拟语气形式因时间不同而不同，这叫做混合条件句。
　　if you had asked him yesterday, you would know what to do now.
　 （从句与过去事实相反，主句与现在事实相反。）
　　if it had rained last night (过去), it would be very cold today (现在).



16.4 虚拟条件句的倒装

　　虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略，再把were, should或had 移到从句句首，实行倒装。
　 were they here now, they could help us.
　=if they were here now, they could help us.
　 had you come earlier, you would have met him
　=if you had come earlier, you would have met him.　
　 should it rain, the crops would be saved.
　=were it to rain, the crops would be saved.

注意：
　 在虚拟语气的从句中，动词'be'的过去时态一律用"were"，不用was， 即在从句中be用were代替。
　 if i were you, i would go to look for him.
　　 如果我是你，就会去找他。
　 if he were here, everything would be all right.
　　 如果他在这儿，一切都会好的。

典型例题
　_____ to do the work, i should do it some other day.
a. if were i　　 b. i were　c. were i　d. was i
　 答案c. 在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前, 变成 were, should, had +主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说 were i not to do., 而不能说 weren't i to do.



16.5 特殊的虚拟语气词：should

1） it is demanded / necessary / a pity + that…结构中的主语从句的谓语动词要用should 加动词原形， should 可省略。

句型：
　　　　(1)suggested
it is　 (2)important　　　　that…+ (should) do
　　　　(3) a pity

(1)suggested, ordered, proposed, required,　 demanded, requested, insisted； + (should) do
(2)important, necessary, natural, strange
a pity,　 a shame,　 no wonder
(3)it is suggested that we (should) hold a meeting next week.

　 it is necessary that he (should) come to our meeting tomorrow.

2）在宾语从句中的应用
　　在表示命令、建议、要求等一类动词后面的从句中。
order, suggest, propose, require, demand, request, insist, command, insist + (should) do
　 i suggest that we (should) hold a meeting next week.
　 he insisted that he (should ) be sent there.

　注意： 如suggest, insist不表示"建议" 或"坚持要某人做某事时"，即它们用于其本意"暗示、表明"、"坚持认为"时，宾语从句用陈述语气。
　 the guard at gate insisted that everybody obey the rules.　

　判断改错:
　（错）　you pale face suggests that you (should) be ill.
　 (对)　 your pale face suggests that you are ill.
　 (错)　 i insisted that you ( should) be wrong.
　 (对)　 i insisted that you were wrong.

3）在表语从句，同位语从句中的应用
　　在suggestion, proposal, idea, plan, order, advice等名词后面的表语从句、同位语从句中要用虚拟语气，即（should）+动词原形。
　　 my idea is that we (should) get more people to attend the conference.
　　 i make a proposal that we (should) hold a meeting next week.



16.6 wish的用法

1）用于wish后面的从句，表示与事实相反的情况，或表示将来不太可能实现的愿望。其宾语从句的动词形式为：

　　　　　　　　　　　　　 真实状况　wish后　　　　 　
从句动作先于主句动词动作　　现在时　　过去时
（be的过去式为 were）　　　　　　　　　　　　　　　 　
从句动作与主句动作同时发生　过去时　　过去完成时
（had + 过去分词）　　　　　　　　　　　　　　　　　　
将来不大可能实现的愿望　　　将来时　would/could +
　　　　　　　　　　　　　　　　　　　动词原形　　　　

　i wish i were as tall as you.　我希望和你一样高。
　he wished he hadn't said that. 他希望他没讲那样的话。
　i wish it would rain tomorrow. 我希望明天下雨就好了。

2）wish to do表达法。
　 wish sb / sth to do
　 i wish to see the manager. = i want to see the manager.
　 i wish the manager to be informed at once. (= i want the manager to be informed at once.)



16.7 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。
　　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。



16.8 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。
　 it is time that the children went to bed.
　 it is high time that the children should go to bed.



16.9 need "不必做"和"本不该做"

　didn't need to do表示： 过去不必做某事, 事实上也没做。.
　needn't have done表示： 过去不必做某事, 但事实上做了。
　john went to the station with the car to meet mary, so she didn't need to walk back home. 约翰开车去车站接玛丽，所以她不必步行回家了。
　john went to the station with the car to meet mary, so she needn't have walked back home. 约翰开车去车站接玛丽，所以她本不必步行回家了。 (mary步行回家，没有遇上john的车。)

典型例题
　there was plenty of time. she ___.
a. mustn't have hurried　 b. couldn't have hurried　　c. must not hurry　 d. needn't have hurried
　答案d。needn't have done. 意为"本不必"，即已经做了某事，而时实际上不必要。
　mustn't have done 用法不正确，对过去发生的事情进行否定性推断应为couldn't have done, "不可能已经"。 must not do 不可以（用于一般现在时）。

虚拟语气
概念
虚拟语气用来表示说话人的主观愿望或假想,而不表示客观存在的事实,所说的是一个条件,不一定是事实,或与事实相反.虚拟语气通过谓语动词的特殊形式来表示.英语中的语气分为陈述语气、祈使语气、虚拟语气三类.
应用条件
　　在表示虚假的、与事实相反的或难以实现的情况时用虚拟语气,表示主观愿望或某种强烈情感时,也用虚拟语气.即当一个人说话时欲强调其所说的话是基于自己的主观想法,而不是根据客观实际,就用虚拟语气.
在非真实条件状语从句中的用法
真实条件状语从句与非真实条件状语从句
条件句可分为两类,一类为真实条件句,一类为非真实条件句.非真实条件句表示的是假设或实际可能性不大的情况,故采用虚拟语气.　　
例： If he doesn’t hurry up, he will miss the bus. 如果他不快点,他将错过巴士.( 真实)　　If he is free, he will ask me to tell stories. 如果他是空闲的,他会要求我讲故事.（真实）　　If I were you, I would go at once.如果我是你,我马上就会去. （非真实,虚拟语气）　　If there were no air, people would die. 如果没有空气,人就会死亡.（非真实,虚拟语气）
用法及动词形式

从句主句
与现在事实相反If+主语+did
（be动词were）主语+should/would/
could/might+do
与过去事实相反If+主语+had done主语+should/would/
could/might+have done
与将来事实相反1.If+主语+did
2.If+主语+were to
3.If+主语+should主语+should/would/
could/might+do
例句：
表示与现在事实相反的情况：　　　例： 1. If I were you, I would take an umbrella.　　如果我是你,我会带把伞.（事实：我不可能是你）　　2.If I knew his telephone number, I would tell you.　　如果我知道他的电话号码,我就会告诉你.（事实：不知道）　　3.If there were no air or water, there would be no living things on the earth.　　如果没有水和空气,地球上就不会有生物.(事实：地球上既有空气也有水)　　4.If I had any money with me, I could lend you some.　　如果我带钱了,我就会借给你些.（事实：没带钱）　　5.If he studied harder, he might pass the exam.　　如果他再努力些,就能通过考试了.（事实：没有努力）　　　2、表示与过去事实相反的情况　　例：1. If I had gotten there earlier, I should/could have met her. 如果我早到那儿,我就会见到她.　　（事实：去晚了）　　2.If he had taken my advice, he would not have made such a mistake. 如果他听我的劝告的话,就不会犯这样的错误了.　　（事实：没有听我的话）　　
表示对将来情况的主观推测,与将来事实相反 例：1.If he should come here tomorrow, I should/would talk to him.　　如果他哪天来这儿的话,我就跟他谈谈. （事实：来的可能性很小）　　2.If there were a heavy snow next Sunday, we would not go skating.　　如果下周日下大雪,我们就不能去滑冰了.（事实：不知能否下雪）　　3.If she were to be there next Monday, I would tell her about the matter.　　如果她下周一来这儿的话,我就会告诉她这件事的始末.　　
有时,虚拟条件句中,结果主句和条件从句的谓语动作若不是同时发生时,虚拟语气的形式应作相应的调整.　　
①从句的动作与过去事实相反,而主句的动作与现在或现在正在发生的事实不符.　　如：　　If I had worked hard at school, I would be an engineer, too.　　如果我在学校学习刻苦的话,我现在也会成为一个工程师了　　If they had informed us, we would not come here now.　　如果他们通知过我们的话,我们现在就不会来这里了.　
②从句的动作与现在事实相反,而主句的动作与过去事实不符.　　如：　　If he were free today, we would have sent him to Beijing.　　如果他今天有空的话,我们会已经派他去北京了.　　If he knew her, he would have greeted her.　　要是他认识她的话,他肯定会去问候她了.　　
当虚拟条件句的谓语动词含有were, should, had时,if可以省略,这时条件从句要用倒装语序,即将were, should, had等词置于句首,这种多用于书面语.　　如：　　Should he agree to go there, we would send him there.　　要是他答应去的话,我们就派他去.　　Were she here, she would agree with us.　　如果她在这儿的话,她会同意我们的.　　Had he learnt about computers, we would have hired him to work here.　　如果他懂一些电脑知识的话,我们已经聘用他来这里工作了.　　
非真实条件句中的条件从句有时不表达出来,只暗含在副词、介词短语、上下文或其他方式表示出来,这种句子叫做含蓄条件句,在多数情况下,条件会暗含在短语中,如without…., but for….等
如：　But for his help, we would be working now.　　要不是他的帮助,我们还会在工作呢.　　Without your instruction, I would not have made such great progress.　　要是没有你的指导,我不会取得如此大的进步.　　We didn’t know his telephone number; otherwise we would have telephoned him.　　我们不知道他的电话号码,否则我们就会给他打电话.　　
有时,虚拟条件句中,主、从句可以省略其中的一个,来表示说话人的一种强烈的感情.　　
①省略从句　　He would have finished it. 他本该完成了.　　You could have passed this exam. 你应该能通过这次考试了.　　
②省略主句　　If I were at home now. 要是我现在在家里该多好啊.　　If only I had got it. 要是我得到它了该多好啊.、
虚拟语气的其他用法
用在wish 后的宾语从句
a、表示与现在事实相反的愿望,谓语动词用过去式　　
eg. I wish I had your brains.　　我希望我有你那样的头脑.(事实：我根本比不上你)　　
b、表示与过去事实相反的愿望,谓语动词：had+done　　
eg: I wish I had known the truth of the matter.　　我希望我原来知道这件事的真相.（事实：原来不知道）　　
c、表示将来难以实现的愿望,谓语动词：should/would + 动词原形
eg. I wish I should have a chance again.　　我希望我还能有一次这样的机会.（事实：很难再有这样的机会了）　　
(注：if only和as if/as though也有相同用法）
用在目的状语从句中
　　1.在for fear that, in case, lest引导的从句中,若用虚拟语气时,从句谓语为：should + 动词原形.并且 should不能省略
eg.She examined the door again for fear that a thief should come in.　　她又把门检查了一遍,以防盗贼的进入.　　He started out earlier lest he should be late.　　他很早就出发了以防迟到.　　
在so that, in order that所引导的目的状语从句中,从句中的谓语为：can / may / could / might / will / would / should + 动词原形.　　
eg.He goes closer to the speaker so that he can hear him clearer. 他走近说话的人以便能听得更清楚.　　He read the letter carefully in order that he should not miss a word. 他把信读得很仔细以便不漏掉一个单词.
其他用法
1、一想要(desire)二宁愿(prefer)三命令(order, command)四建议(advice. Suggest, propose)五要求(demand , require, request , desire , insist)中,无论主句谓语动词为何种时态,从句的谓语动词都用：“should + 动词原形”或只用“动词原形”.　　如：　　He suggested that we (should) takethe teacher’s advice.　　He insisted that we (should) takethe teacher’s advice.　　He demand that we (should) takethe teacher’s advice.　　He ordered that we (should) takethe teacher’s advice.　　
insist如果翻译成坚持某种动作才用虚拟语气；翻译成坚持某种观点就不用虚拟语气.
　　　如：He insist he is a student.　　他坚持说他是个学生.　　这个语句表示的是事实,因此在这个语句中不能使用虚拟语气.　　
suggest意为“建议”才用虚拟语气,意为“暗示”则不用虚拟语气.　　如： His face suggests that he looks worried .　　他的表情暗含着他很担心.　　这个句子本身是事实,因此它就没有用到虚拟语气.　　
2、表情绪.观点的形容词或名词也要用虚拟语气.如:necessary、important、impossible、natural、strange、surprising、funny、right、wrong、better、a pity等.
句型：It is.that +主语从句,从句的谓语动词都要用should+原型 或只用动词原型.　　
在even if, even though 所引导的让步状语从句中,可用虚拟语气,主句、从句的结构与if所引导的条件从句结构相同.如：　　Even if he were here himself, he should not know what to do.　　即使他亲自来也不知该怎么办.（事实：他没来）　　Nobody could save him even though Hua Tuo should come here.　　即使华佗在世也救不了他.（事实：华佗不在世）　　
在whatever,whichever,whenever,whoever, wherever,however, no matter wh-word 等引导的让步状语从句中,从句虚拟语气结构为：　　指现在或将来： may +动词原形.　　如：　　We will finish it on time no matter what may happen.　　不管发生什么事,我们都要按时完成.　　We will find him wherever he may be.　　无论他在哪里,我们都要找到他.　　I will wait for him no matter how late he may come.　　不管他来的多么晚,我都会等他.　　指过去： may +完成式 .　　如：　　You mustn’t be proud whatever great progress you may have made.　　不管你取得了多么大的进步,你也不能骄傲.　　We must respect him no matter what mistakes he may have made.　　不管他犯过什么错误,我们必须尊敬他.　　
5、一般would rather, had rather, would sooner等之后的宾语从句常表示与客观事实不相符的一种愿望,故使用虚拟语气.其虚拟语气的结构为：　　
过去: had + 过去分词 ; 现在: 过去时(be用were ) ; 将来: 过去时(be用were )　　如：　　I’d rather you had seen the film yesterday.　　我倒想你昨天看过了这场电影.　　I’d rather you were here now.　　我倒想你现在在这儿.　　We’d rather you went here tomorrow.　　我们倒想你明天去那儿　　
虚拟语气还可用在定语从句中,表示：“早该做某事了”时,定语从句中的谓语动词须用虚拟语气,其虚拟语气的结构为：It is (high / about) time that + 主语+ 动词的过去式/ should + 动词原形,即从句用虚拟过去式.　　如　　It is time that I went to pick up my daughter at school.　　我该去学校接我的女儿了.　　It is high time you should go to work.　　你早该上班了.　　
简单句中的虚拟语气　　
说话时,为了表示客气、谦虚、委婉而有礼貌,言语常使用虚拟语气.其虚拟语气的结构形式常为：would / could / might / should + 动词原形.　　如：　　Would you mind my shutting the door?　　我把门关起来你介意吗?　　You should always learn this lesson by heart.　　你要把这个教训牢记于心.　　I should agree with you.　　我应该同意你的观点.　　
表示“祝愿”时,常用may + 主语+ 动词原形.　　如：　　May you have a good journey!　　祝你一路顺风.　　May your youth last for ever!　　祝你青春永驻.　　
（3）表示强烈的“愿望”、“祝愿”时,常用动词原形.　　如：　　Long live the Communist Party of China.　　中国共产党万岁.　　God bless us.　　上帝保佑.　　
（4） 习惯表达中常用的虚拟语气.
① 提出请求或邀请.如：　　Would you like to have a talk with us this evening?　　今天晚上来跟我们聊天好吗?　　Could I use your bike now?　　我可以用一下你的单车吗?　　② 陈述自己的观点或看法.如：　　I should glad to meet you.　　见到你我会很高兴.　　I would try my best to help you.　　我会尽力帮助你.　　③提出劝告或建议.如：　　You’d better ask your father first.　　你最好先问一问你的父亲.　　You should make a full investigation of it first.　　你应该先全面调查一番.　　④ 提出问题.如：　　Do you think he could get here on time?　　你认为他能按时来吗?　　Do you expect he would tell us the truth?　　你期望他会告诉我们真相吗?　　⑤ 表示对过去情况的责备时,常用虚拟语气.其虚拟语气的结构为：情态动词 + have + 过去分词.　　如：　　You should have got here earlier. 你应该早就到这里了.　　You should have returned it to him. 你应该把它还给他了.　　
省略的虚拟条件句型
省略连词if
有时可将条件从句的连词if省略,但此时应用倒装句型,即将从句中的were, should, had 等提到句首：　　Were I Tom, I would refuse. 如果我是汤姆,我会拒绝.　　I will go, should it be necessary. 假若有必要,我会去的.　　Had it not been for the bad weather we would have arrived in time. 若不是天气坏,我们就准时到达了.　　
【注】　　① 若条件从句为否定句,否定词not应置于主语之后,而不能与were, should, had 等缩略成Weren’t, Shouldn’t, Hadn’t而置于句首.　　② 有时省略if后提前的had不是助动词：　　Had I time, I would come. 假若我有时间,我会来的.(=If I had time…)
省略条件句的主语和其后的动词be
　　若主从句主语一致,且谓语部分包含有动词be,通常可将主语和动词be省略：　　If repaired earlier, the tractor would not have broken down.　　要是早点儿修一下,拖拉机就不会抛锚了.(=If it had been repaired earlier…)
省略“it+be”
　　If necessary, I would send more farm-hands to help you.　　如果需要的话我会派更多的民工去帮你.(=If it was necessary, I would…)
省略整个条件从句
　　这样的省略通常需要借助一定的上下文,即省略条件从句后,所剩下的主句的意思在一定的上下文中意思是清楚的：　　I might see her personally. It would be better. 我可以亲自去看她,这样好一些.(=…If I saw her personally, it would be better.)
在含蓄条件句中的用法
　(1) 条件暗含在短语中.如：　　We didn’t know his telephone number; otherwise we would have telephoned him.　　我们不知道他的电话号码,否则我们就会给他打电话.（暗含条件是otherwise）　　Without your help, we wouldn’t have achieved so much.　　没有你的帮助,我们不可能取得这么大的成绩.　　（暗含条件是介词短语without your help）　　But for your help, I would not have succeeded in the experiment.　　如果没有你的帮助,我的实验就不会成功.（暗含条件是but for your help）　　It would cause great trouble not to lubricate the bearing immediately.　　不立即润滑轴承就会引起很大的故障.　　（暗含条件是not to lubricate the bearing immediately）　　(2) 条件暗含在上下文中.如：　　I would not have done it that way.　　我是不会那么做的.（可能暗含if I were you）　　I was busy that day. Otherwise I would have come to help you.　　我那天很忙.否则我会来帮你的.（可能暗含if I hadn’t been so busy.）　　You might come to join us in the discussion.　　你可以参加我们的讨论.（可能暗含if you wanted to）　　I would have bought the DVD player.　　我是会买下那台影碟机的.（可能暗含if I had the money）　　But for the storm, we should have arrived earlier.　　要不是碰到暴雨,我们还会早些到.（可能暗含if it had not been for the storm）.