1、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). 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 th
2、ey 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 b
3、e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 IB. 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
4、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 Werent I to do. 5特殊的虚拟语气词：should1） 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)suggestedIt is (2)important that+ (should) do(3) a pity(1)suggested, ordered, proposed, required, deman
5、ded, requested, insisted； + (should) do (2)important, necessary, natural, strangea 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, de
6、mand, 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 pa
7、le 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)
8、get more people to attend the conference.I make a proposal that we (should) hold a meeting next week. 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 过去时 过去完成时（be 的过去式为 were） 从句动作与主句动作同时发生 现在时 过去时（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
9、 tall as you. 我希望和你一样高。He wished he hadnt 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 doI 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.) 7.比较 if only
10、与 only ifonly 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。 8.It is (high) time thatIt 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 th
11、e children went to bed.It is high time that the children should go to bed. 9 need “不必做“和“本不该做“didnt need to do 表示： 过去不必做某事, 事实上也没做。.neednt 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 didnt 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 sta
12、tion with the car to meet Mary, so she neednt 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. mustnt have hurried B. couldnt have hurried C. must not hurry D. neednt have hurried答案 D。neednt have done. 意为“本不必“ ，即已经做了某事，而时实际上不必要。Mustnt ha
13、ve done 用法不正确，对过去发生的事情进行否定性推断应为 couldnt have done, “不可能已经“ 。 must not do 不可以（用于一般现在时） 。 语气是一种动词形式，用以表示说话者的意图或态度。虚拟语气表示说话者的主观愿望、假想和建议等，所说的话有的与现在事实相反，或与过去事实相反，或与将来事实相反或与将来事实可能相反。所以虚拟语气总是与假设条件句用在一起。除了 if 条件句外，还有几种常用的条件句，短语也可表示条件。此外，上下文也能创造虚拟的语言环境。但有时条件从句与结果主句可能发生时间不一致，有时虚拟语气会出现倒装情况。除了与条件句在一起使用的主句用虚拟语气外
14、，有些宾语从句或表语从句也有用虚拟语气的情况。 I 虚拟语气的形式与基本用法 一、虚拟语气的形式 虚拟(条件) 语气中，主句与从句中谓语动词的形式可分为下面四类 假设类型 条件从句谓语动词形式 主语谓语动词形式 与现在事实相反 动词的过去式(be 用 were 而不用 was) would(第一人称可用 should)+动词原形 与过去事实相反 had+ -ED 分词 would(第一人称可用 should)+have + -ED 分词 与将来事实相反 were to + 动词原形 would(第一人称可用 should)+动词原形 与将来事实可能相反 should + 动词原形 would(
15、第一人称可用 should)+动词原形 二、虚拟语气的基本用法1. 与现在的事实相反Top grade A diamonds had not B increased so sharply C in value in the late seventies D if one company had not controlled almost all of the worlds supply. 3. 与将来的事实相反 4. 与将来的事实可能相反 (1) If it should rain tomorrow, I would stay at home. 要是万一 明天下雨，我就呆在家里不出去。 事实上
16、 现在天气很好，明天下雨的可能性应该不大，不过也说不准。 (2) If I should see her next Monday, I would tell her about it. 如果下周一我能见到她的话我就把这件事告诉她。II 虚拟语气的特殊表现形式 一、表示“好像” ：除了 if 条件从句外，由 as if 和 as though 等引导的状语从句表示方式时，意思是“好像” ,这时从句中的谓语动词应用虚拟语气。其动词形式用过去时(be 用 were的形式)表示所说的与现在的事实相反；用过去完成时表示所说的与过去的事实相反 二、特殊连词的需要：lest, for fear that 和
17、 in case 引起的从句(这时谓语多用 should加动词原形)We dare not play jokes on Mr. Wang lest he should become angry. (我们不敢跟王先生开玩笑，恐怕他生气。) He hurried on, lest he should drop out in the forced match. (他加紧步伐，生怕在急行军中掉队。) Every attention must be paid to him lest he (should) feel that he is inferior to my other guests. (我对他
18、特别关照，唯恐他感觉到比我的其他客人低人一等。) Hes working hard for fear that he should fail in the exam. (他加紧学习唯恐考试不及格。)三、介词短语表示虚拟： 有时假设的情况并不以条件从句表示出来，而是通过一个介词短语来表示，或通过上下文或其他方式表示出来。如 but for, but that, in case of, otherwise, supposing, under more favourable condition, without 等表示让步假设 He worked very hard; otherwise he mi
19、ght have failed. (他刻苦工作，不然他就失败了。) We could have done better under more favorable conditions.(假设我们有更有利条件，我们还会做得更好。) 四、虚拟错综条件句：上面几种假设类型中，主句与从句的谓语动词形式应前后呼应。但是，如果主句与从句的动作发生的时间不一致，谓语动词形式应做适当调整 If I had a bike(now), I would have lent it to you yesterday. 假如我有自行车，昨天早就借给你了。(主句与过去事实相反，从句与现在事实相反。) I am very s
20、orry if I had done anything wrong to you, but I am sure that it was unintentional.(如果我当时对你作错了什么事，我向你表示抱歉。但我敢保证我不是故意的。) 五、省略虚拟条件句：虚拟条件从句中的谓语动词如果是 were 或 should(could, might), had 等词时，可以省略连词 If, 但要将 were 或 should(could, might), had 助动词移至主语前形成句子例装(参见第十三章 “倒装句”) III 从句中须用虚拟语气的情况 一、在 wish 的宾语从句中 1. 动词 wi
21、sh 后跟由 that 引导的宾语从句(that 经常被省略 )要用虚拟语气表示一种不可实现的愿望。宾语从句中用过去时(be 用 were 的形式)表示与现在事实相反,用过去完成时表示与过去相反 She wishes she had more money. (她真希望有更多的钱。) / I wish I didnt say that. (要是我不说这件事就好了。) / I wished I were not so worried. Then I would not have had the accident. ( 我要是不那么忧郁就好了，那也就不会发生那场事故了。) 2. 当 wish 的宾语
22、从句表示一种愿望、要求时，可用过去时，也可用 would动词原形 I wish you would stay here longer. (我希望你在这儿多呆一会。 ) / She wishes you wouldnt go. (她希望你不要走。) 3. would rather(宁愿),would sooner(宁愿), had rather(宁愿) 等词或短语后面的从句中的谓语动词应使用一般过去时表示虚拟语气，表示与过去相反的也可用过去完成时 二、在某些特殊概念词的宾语从句中：一些表示提议、主张、要求、命令、紧要等概念的词语，由于它们本身隐含说话者的主观意见，认为某事应该或不应该怎样，这些词
23、语后面的“that”从句应用虚拟语气，且均以“should”表示这种语气，但事实上“should” 常被省略，故此从句中谓语动词用原形。这些词可分为下列几类 1. 下列动词后“ that”引导的宾语从句 suggest(建议) ， propose (提议)， recommend(建议)， move (提议)， advise(建议)，insist(坚持)， urge(极力主张) ， ask, require, request(要求), demand, desire, order, command(命令), decide, intend(打算)， prefer(宁愿) ， urge(敦促)。 Wh
24、en I suggested that he try shaving cream, he said, “The razor and water do the job. ” (当我建议他用刮胡膏时，他说“ 剃刀和水就行了”。)He pursued various theories for several days until I suggested we take the toy apart to see how it did work. (他费了几天功夫寻找理论根据，直到我建议拆开看看它是如何转动的。)One can suggest that students should spend two
25、 or three years in an Englishspeaking country. (我们建议学生应在说英语的国家呆上两三年。)2. 下列表示主张、要求、命令、愿望、建议等概念结构后的主语从句或逻辑上的主从结构(如下列形容词作宾语从句的补足语时，这时宾语从句一般用 it 来代替) ：这时 that 所引导的主语从句中的谓语动词常用“should 动词原形”或省略 should，只用动词原形it is necessary 【 essential (重要的) ， vital(极重要的，不可缺少的) ，important,imperative(必须的)，urgent(紧要的) ，advis
26、able(应该的)，proper(适当的)，obligatory (必须的 )，desirable(今人满意的，值得的)，appropriate(合适的) ，fitting (合适的), strange (奇怪)】that； it is(was, has been) desired 【suggested , requested, ordered , proposed, dicided】 that .虚拟语气是以动词的特殊形式来说明句中所叙述的内容不是事实，或是不可能发生的事情，而是一种愿望、建议或是与事实相反的一种假设。虚拟语气通常出现在各种主从复合句中。一、在宾语从句中1当主句的谓语动词为“
27、suggest，propose，advise，insist，order ，demand，require，request， desire等表示“建议”、 “命令 ”、 “请求” 和“ 要求”的动词时，其后的宾语从句中要用虚拟语气“should+动词原形”(在美国英语中 should 省略)。例如：I suggest that we(should)hold a meeting tonight我建议我们今晚开个会。We advise that steps(should)be taken at once我们建议要立刻采取措施。They insisted that he(should)begin the
28、 work at once他们坚持让他立刻开始工作。He ordered that aU(should)take part in the work他下令所有的人都要参加这项工作。另外，当主句动词为“ask，move，urse ”等意为 “要求”、 “提议”和“极力主张” 时，其宾语从句也常用虚拟语气。例如：He asked that he be given an opportunity to try他要求给他一个尝试的机会。I move that the money be used for books 我提议把这笔钱用于买书。They urged that we take action on
29、this matter immediately他们极力主张我们对这件事立即采取行动。2当主句动词为 wish，表示“但愿” ， “要是该多好叼” 之意时，其后的宾语从句有以下三种虚拟语气形式。动词用过去式来说明与现在的事实相反(BE 动词常用 were，但有时也可用 was)。例如：1 wish 1 wereWas as strong as you我要是像你一样强壮就好了。1 wish l remembered his address我要是记住他的地址就好了。有时；为了强调现在状态下能发生某种情况或进行某项动作，从句中的动词也可用过去进行式。例如：1 wish it wasnt raining
30、要是天不下雨就好了。动词用过去完成式说明与过去的事实相反。例如：We wish we had paid more attention to our pronunciation我们以前要是能更注意我们的发音就好了。He wished he had stayed at home。他但愿他呆在了家里。情态动词“would，could，might ”等后接动词原形，表示对将来的希望( 通常不用should)。例如：1 wish he would try again我希望他再试一下。We wish he could come我们希望他能来。3在 prefer 之后的宾语从句中用“should+动词原形”
31、(should 可省略) 。例如：We prefer that the plan(should)be fully discussed before being put into execution我们希望在计划实施之前进行认真的讨论。4在 would rather 之后的宾语从句中，其动词用虚拟语气，表示句子的主语(某人) 宁愿让另一人做某事。用动词过去式表示现在或将来要做的事。例如：Id rather you went home now我宁愿让你现在就回家。Dont come tomorrowId rather you came nextweekend明天别来，我宁愿你下个周末来。一 Sha
32、ll l open a window?我开窗行吗？ 一 Id rather you didnt你最好别开。用动词的过去完成式表示过去的动作。例如：Id rather you hadnt done that我真希望(宁愿) 你没做过那件事。二、在主语从句中1在句型“h iswas+过去分词 +that 从句” 中，当过去分词为“suggested，ordered，desired，insisted ， required，demanded ，requested，decided，proposed，urged 等时，从句中要用“should+动词原形” (should 可省略) 。例如：h is des
33、ired that everyone(should)get erything ready bY toniShL 要求每一个人在今晚之前要将一切准备好。It is requested that Miss Zhang(should) give a performance at the party请求张小姐在晚会上表演一个节目。2在句型“h isWas+形容词+that 从句” 中，当形容词为“important,necessary，strange ，natural等时，从句中要用 “should+动词原形”(should 可省略)。例如：It is important and necessary
34、that we should master a foreign language掌握一门外语对我们来说是重要的和必要的。It is strange that he (should) refuse your help他竟然拒绝你们的帮助，真奇怪。3在句型“h iswas+名词 +that 从句” 中，当名词为“a pity，a shame，no wonder等时，从句中要用“should+动词原形”(should 可省略) 。例如：It is a great pity that he should be so selfish。真遗憾，他竟然那么自私。三、在同位语从句或表语从句中在名词“sugge
35、stion,proposal,idea,plan ，order,advice等后面的同位语从句或表语从句中，用“should+动词原形” (should 可省略) 。例如：I made a proposal that we(should)hold a meeting next week我提出了我们下个星期开会的建议。(同位语从句)His suggestion that the meeting(shoald)be held in this room has been accepted他的关于在这个房间召开会议的建议被采纳了。(同位语从句)My idea is that we(should)get
36、 more people to attend the conference我的想法是我们多找些人来参加会议。(表语从句 )四、在定语从句中在句型“h is(high)time+(that)从句”中，谓语须用虚拟语气。用过去式表示现在或将来的意念，意为“现在是该做某事的时候了”。例如：h iS(hieh)time(that)we went home我们该回家了。五、在状语从句中1在假设条件句的 if 条件从句中假设条件句一般是由“if 引导的条件从句+主句” 构成。if 从句中的谓语动词要用虚拟语气的形式。if 从句的假设可以是与现在事实相反的条件、与过去事实相反的条件或者与将来不太可能成为事实
37、的条件。下面分述表示这三种条件的 if 从句的结构：与现在的事实相反，其句子结构为“If+主语+were谓语动词的过去式”。例如：If 1 were you，I shouldnt do that如果我是你，就不会做那件事了。We would go with you if we had time如果我们有时间的话，就和你一道去了。We could ask him if he were here如果他在这儿，我们就可以问他了。与过去的事实相反，其句子结构为“If 十主语+谓语动词的过去完成式”。例如：If he had seen you yesterday，he would have asked
38、you about it 如果昨天他见到你，他就会问你那件事了。If you had come earlier，you would have met him如果你早点儿来，就会遇到他了。1 would have called you if I had known your telephone number如果我知道你的电话号码，就打电话给你了。表示将来不太可能实现的条件，其句子结构为“If+主语+动词过去式were to+动词原形should+动词原形”。例如：If he came tomorrow,he would find me in the schoo1如果他明天来的话，会在学校找到我。
39、If it should rain，the crops would be saved如果下雨，庄稼就有救了。If it were to snow tomorrow，they would not go out如果明天下雪，他们就不出去了。注：在 if 从句中，如果含有“were，should，had时，可省去 if 而将“were，should，had 置于句首，构成倒装句。例如：Were l in your position，1 would go如果我处在你的位子上，我就走了。Had you arrived five minutes earlier，you could have seen th
40、em off如果你早到五分钟，你就可以给他们送行了。Should he come，tell him to ring me up如果他来的话，叫他打电话给我。2在目的状语从句中在由 lest和 in case 等引导的目的状语从句中，用“ should+动词原形” (should 可省略)。例如：He ran away lest he(should)be seen他跑走了，以免被人看到。She explained again and again in case he (should)misunderstand her她解释了一遍又一遍，以免他误解她。in case 等引导的目的状语从句中的谓语有
41、时也可用陈述语气。此时，从句表示的就是真实情况，而不是虚拟情况。例如：Take warm clothes in case the weather is cold带上厚衣服，以防天气变冷。在由 “so that”和“in order that”引导的目的从句中，要用“cancould maymight would+动词原形” ，以表示目的并非事实。例如：She stayed at home for a few days so thatshe might could take care of her sick mother 她在家呆了几天，以便照顾她生病的母亲。在由 “for fear that”
42、引导的从句中，用“should+动词原形”( 有时也可用maymightwould)。例如：He worked hard for fear that he should fail他努力学习，害怕考试不及格。3在方式状语从句中由 as if 和 as though 等引导的方式状语从句中，如果从句所表达的情况是虚拟的，则常用动词的过去式来表示与现在或当时的情况相反；如果是 BE 动词，则用 were；常用过去完成式来表示与过去的情况相反。例如：She loves the child as if he were her own她爱这孩子就好像是她亲生的。(实际上不是她亲生的孩子)Holding h
43、is head high，he walked past the pole and the soldiers as if they didnt exist他昂着头从旗杆和卫兵身旁走过，就像他们不存在似的。(实际上他们是存在的)He speaks English as well as ifhe hadstudied in England他英语说得这么好，好像他去英国学过英语似的。(实际上他没有在英国学过英语 )4在原因状语从句中在“Im sorry that We were surprised that 一They were disappointed that ”等引导的表示原因的状语从句中，用“should 十动词原形” 。例如：Im sorry that he should be in such poor health他的身体这么差让我很难过。We were surprised that she should be so stubbom她这么固执让我们感到奇怪。上述句子有时也可以用陈述语气，但这仅表示所叙述的是事实，而不表示讲话人的情绪。
