1、选修6重点语法汇总Unit1虚拟语气的用法虚拟语气表示一种假设的情况，或一种主观的愿望，即动词所表示的动作或状态并非事实，或不可能实现。英语虚拟语气的形式有下列几种：一、虚拟语气用于条件状语从句注意：主句中的should通常用于第一人称，would可用于任何人称,同时也可根据意思用情态动词could, might等代替should, would。1. 与现在事实相反连接词条件从句结果从句If1).动词过去式(或were)2).助动词（过去式）+动词原形Should/Would/Could/might+动词原形If had the time, John would make a trip to
2、China to see the Great Wall.If I were you, I would give up drinking immediately.2. 与过去事实相反连接词条件从句结果从句Ifhad+过去分词Should/Would/Could/might + have+过去分词If Id known that it was going to rain, I would never have gone for a walk in the country.3. 与将来事实相反连接词条件从句结果从句If1.should+动词原形2.动词过去式3. were to+动词原形Should
3、/Would/could/might+动词原形If it were to/should rain tomorrow, the meeting would be put off. If you went there next time, you would see what I mean.4. 错综时间虚拟语气当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时,动词的形式要根据它所表示的时间来调整。例如：If I were you, I would have gone home.（从句说的是现在，主句指的是过去。）If you had followed the doctors advi
4、ce, you would be quite all right now.(从句说的是过去，主句指的是现在。)If the weather had been more favorable, the crops would be growing still better.其它状语从句1. 方式状语as if(as though)如果从句表示与现在事实相反，谓语动词用一般过去时；表示与过去事实相反，谓语动词用had+过去分词；表示与将来事实相反；谓语动词用would(might, could)+动词原形。例如: He looks at me as if I were mad. He spoke E
5、nglish so fluently as if he had studied English in England.但as if(as though)后的从句也常用陈述语气,这是因为从句中的情况往往是可能发生的或可能被设想为真实的。例如: It looks as if our side is going to win.2. 目的状语in order that, so that 从句谓语动词用 may/might, can/could)+动词原形。例如: She listened carefully in order that she might discover exactly what h
6、e wanted. 3. 连词引导的条件状语从句:in case, unless, supposing ,providing, on condition that从句谓语动词用(should)或 might, could)+动词原形。4. 连词引导的步状语从句lest ,for fear that等We hid behind some bushes for fear that passer-by should see us.二、虚拟语气用于宾语从句1. Suggest, advise 等动词之后宾语从句须用虚拟语气，其句子结构如下：要求：ask demand require request b
7、eg plead insist pray urge 建议：suggest advise propose recommend move 命令、决定：order command decide determine resolve其它：consent deserve desire intend maintain prefer等后面的宾语从句中+that(should )+动词原形注意：在此结构中that不可省略；should省不省均可。He suggested that they (should ) stop smoking.They demanded that the black people sh
8、ould be treated as well as white people.如果that 引导的从句所表达的内容是事实，也可用陈述语气。He insists that he is right. 注意:insist作力言、强调解时,宾语从句不用虚拟语气。只有当insist作坚持(应该)解时,宾语从句才用虚拟语气。例如:Mike insisted that he had never stolen anything. I insisted that you give me my money back.2. wish+宾语从句表示不能实现的愿望,汉语可译为可惜、就好了、悔不该、但愿等。表示现在不能
9、实现的愿望,从句的谓语动词用过去式;表示将来不能实现的愿望,用would(could)+动词原形;表示过去不能实现的愿望,用had+过去分词或(could)would+have+过去分词。例如:wish的用法1). 与现在事实相反 :动词过去式或wereI wish we could go to the seaside today. I wish I were a pop singer. (=I am sorry I am not a pop singer.)2).与过去事实相反 : 主语+wish(that)+主语 + 动词过去完成式We wish we had arrived there
10、two hours earlier.I wish I had never stopped teaching. (=I am sorry I stopped teaching.)3).与将来事实相反 :助动词过去式+动词原形I wish theyd let us get some sleep.注意：wish与hope接宾语从句的区别在于：hope表示一般可以实现的希望，宾语从句用陈述语气。wish表示很难或不大可能实现的希望,宾语从句用虚拟语气。试比较：（1） We hope they will come,(We dont know if they can come.)（2） We wish t
11、hey could come,(We know they are not coming.)3. 虚拟语气在would rather/would sooner/would just as soon后接从句:Id rather you paid me now.(从句用过去时指现在) I would rather they came tomorrow.(从句用过去时指将来) Id rather she hadnt done that.(从句用过去完成时指过去)(此句中的would可看作是表愿望的实义动词)三、虚拟语气用于主语从句在主语从句中，谓语动词的虚拟语气结构用should+动词原形的结构，表示
12、惊奇、不相信、惋惜、理应如此等。例如:It is necessary( appropriate/ crucial / desirable/dreadful / essential/important /improper incredible/ indispensable / insistent /natural / preferable / possible / probable/ proper / right /.significant / surprising /strange/ tragic / urgent /vital /wrong etc.)that we should clean
13、 the room every day. It was a pity(a shame, no wonder, etc.)that you should be so careless. It will be desired(suggested, decided, ordered, requested, proposed,etc.)that she should finish her homework this afternoon.a在上述三种主语从句中,should意为应该、竟然,可以省去,但不可换用would。主句所用动词的时态不限。注意：这种从句表示的是事实。如果说话人对这种事实表示惊奇,就
14、可用虚拟语气。反之，如果不表示惊奇，that从句也可用陈述语气。例如:It is strange that he did not come yesterday. It is a pity that you cant swim.四、虚拟语气用于表语从句、同位语从句要求：demand requirement request motion pray insistence 建议：suggestion advice proposal recommendation motion命令、决定：order command decision determination resolution其它：plan desi
15、re idea necessity preference等名词的表语从句和同位语从句,其谓语动词要用虚拟语气的结构(should)+动词原形。例如:We all agreed to his suggestion that we(should)go to Beijing for sightseeing. My idea is that he (should)do exercises first.五、虚拟语气的几种特殊用法1. 省掉if的条件从句倒装结构：(should, had, were)Had you asked me, I would have told you. (=If you had
16、 asked me,)Were I you, I would be back home. (= If I were you, )Should I know it, I would tell you. (= If I should know it, )2. 有时虚拟条件不用条件从句而用不定式、分词、介词、名词、连接词或定语从句来表示，如：Atrue friend would not do such a thing. (=If he were a true friend, he.) Without water, we would not live. (=If there were no water
17、,) But for your help, I couldnt have finished it.(=If you hadnt helped me,)3. 虚拟语气用于定语从句:Its (high) time that+动词过去式或should+动词原形， (should不能省略,be用were)来表示,意为(现在)该。如：Its time (that) you had a hair cut.Its high time (that) we took some action.4. 虚拟语气用于if only引导的感叹句:If only I had taken his advice.我要是听他的话
18、就好了。If only I were a bird!我如果是一只鸟就好了。5. 虚拟语气用于简单句1) 表示说话人谦虚、客气、有礼貌,使语气委婉,常出现在日常会话中。例如:It would be better for you not to stay up too late. Would you be kind enough to open the door?2)用于一些习惯表达法中。例如:Would you like a cup of tea. You had better go now.3)用may+动词原形,表示祝愿、但愿。may须置于句首。例如:May you be happy!May
19、you succeed!6. 含蓄条件句在某些虚拟语气结构中没有if条件句,虚拟条件是用其它形式表示出来,这种现象在语法上称为含蓄条件句。含蓄条件具体分为以下几种情况:1) 通过动词不定式短语表示条件。例如:You would be a fool to refuse his offer.(=If you should refuse his offer,you would be a fool.)要是你拒绝他的建议,就太傻了。2) 通过介词短语表达条件。例如:But for the storm I would have arrived much earlier.(=If it had not be
20、en for the storm.)要不是那场暴雨,我早就到达了。Without air, there would be no living things. I would not have succeeded but for your help.3) 通过连词otherwise, or, but, that, though, once等表达条件。例如:She came to town yesterday, otherwise/or I would not have met her.昨天她到城里来了,不然我就不会遇见她了。(otherwise/or=if she hadnt come)I wo
21、uld have attended the meeting, but I have been too busy.(=.if I had not been too busy)我本来要参加会议的,只是太忙了。4) 通过Were it not for.或Had it not been for.等句式表达条件。意为如果当时没有,表示同过去事实相反的假设。例如:Were it not for(=If it were not for) the leadership of the Party,we could not live a happy life.要不是党的领导,我们不可能过幸福生活。(与现在事实相反
22、)Had it not been for(=If it had not been for) the leadership of the Party,we should have failed.若不是有党的领导,我们早就失败了。(与过去事实相反)5) 通过分词短语表达条件。例如:Given more attention, the trees could have grown better.倘若给予更多的关心,这些树本来可以生长得更好的。(=If they had been given more attention.)6) 无词句暗示条件。例如:Such mistakes could have b
23、een avoided.这种错误本来可以避免的。(暗含条件从句if we had been more careful)It was so quiet, you could have heard a pin drop.是那样的安静,掉根针你都听得见。(暗含条件从句if it had dropped to the ground)Unit2虚拟语气的用法虚拟语气表示一种假设的情况，或一种主观的愿望，即动词所表示的动作或状态并非事实，或不可能实现。英语虚拟语气的形式有下列几种：一、虚拟语气用于条件状语从句注意：主句中的should通常用于第一人称，would可用于任何人称,同时也可根据意思用情态动词c
24、ould, might等代替should, would。5. 与现在事实相反 连接词条件从句结果从句If1).动词过去式(或were)2).助动词（过去式）+动词原形Should/Would/Could/might+动词原形If had the time, John would make a trip to China to see the Great Wall.If I were you, I would give up drinking immediately.6. 与过去事实相反连接词条件从句结果从句Ifhad+过去分词Should/Would/Could/might + have+过去
25、分词If Id known that it was going to rain, I would never have gone for a walk in the country.7. 与将来事实相反连接词条件从句结果从句If1.should+动词原形2.动词过去式3. were to+动词原形Should/Would/could/might+动词原形If it were to/should rain tomorrow, the meeting would be put off. If you went there next time, you would see what I mean.8
26、. 错综时间虚拟语气当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时,动词的形式要根据它所表示的时间来调整。例如： If I were you, I would have gone home.（从句说的是现在，主句指的是过去。）If you had followed the doctors advice, you would be quite all right now. (从句说的是过去，主句指的是现在。)If the weather had been more favorable, the crops would be growing still better.其它状语从句5.
27、 方式状语as if(as though)如果从句表示与现在事实相反，谓语动词用一般过去时；表示与过去事实相反，谓语动词用had+过去分词；表示与将来事实相反；谓语动词用would(might, could)+动词原形。例如: He looks at me as if I were mad. He spoke English so fluently as if he had studied English in England.但as if(as though)后的从句也常用陈述语气,这是因为从句中的情况往往是可能发生的或可能被设想为真实的。例如: It looks as if our sid
28、e is going to win.6. 目的状语in order that, so that 从句谓语动词用 may/might, can/could)+动词原形。例如: She listened carefully in order that she might discover exactly what he wanted. 7. 连词引导的条件状语从句:in case, unless, supposing , providing, on condition that从句谓语动词用(should)或 might, could)+动词原形。8. 连词引导的步状语从句lest ,for fe
29、ar that等We hid behind some bushes for fear that passer-by should see us.二、虚拟语气用于宾语从句4. Suggest, advise 等动词之后宾语从句须用虚拟语气，其句子结构如下：要求：ask demand require request beg plead insist pray urge 建议：suggest advise propose recommend move 命令、决定：order command decide determine resolve其它：consent deserve desire inten
30、d maintain prefer等后面的宾语从句中 +that(should )+动词原形注意：在此结构中that不可省略；should省不省均可。He suggested that they (should ) stop smoking.They demanded that the black people should be treated as well as white people.如果that 引导的从句所表达的内容是事实，也可用陈述语气。He insists that he is right. 注意:insist作力言、强调解时,宾语从句不用虚拟语气。只有当insist作坚持(
31、应该)解时,宾语从句才用虚拟语气。例如:Mike insisted that he had never stolen anything. I insisted that you give me my money back.5. wish+宾语从句表示不能实现的愿望,汉语可译为可惜、就好了、悔不该、但愿等。表示现在不能实现的愿望,从句的谓语动词用过去式;表示将来不能实现的愿望,用would(could)+动词原形;表示过去不能实现的愿望,用had+过去分词或(could)would+have+过去分词。例如:wish的用法1). 与现在事实相反 :动词过去式或wereI wish we coul
32、d go to the seaside today. I wish I were a pop singer. (=I am sorry I am not a pop singer.)2).与过去事实相反 : 主语+wish(that)+主语 + 动词过去完成式We wish we had arrived there two hours earlier.I wish I had never stopped teaching. (=I am sorry I stopped teaching.)3).与将来事实相反 :助动词过去式+动词原形I wish theyd let us get some s
33、leep.注意：wish与hope接宾语从句的区别在于：hope表示一般可以实现的希望，宾语从句用陈述语气。wish表示很难或不大可能实现的希望,宾语从句用虚拟语气。试比较：（1） We hope they will come,(We dont know if they can come.)（2） We wish they could come,(We know they are not coming.)6. 虚拟语气在would rather/would sooner/would just as soon后接从句:Id rather you paid me now. (从句用过去时指现在)
34、I would rather they came tomorrow. (从句用过去时指将来) Id rather she hadnt done that. (从句用过去完成时指过去)(此句中的would可看作是表愿望的实义动词)三、虚拟语气用于主语从句在主语从句中，谓语动词的虚拟语气结构用should+动词原形的结构，表示惊奇、不相信、惋惜、理应如此等。例如:It is necessary ( appropriate/ crucial / desirable/dreadful / essential/important /improper incredible/ indispensable /
35、 insistent /natural / preferable / possible / probable/ proper / right /.significant / surprising /strange/ tragic / urgent /vital /wrong etc.)that we should clean the room every day. It was a pity (a shame, no wonder, etc.)that you should be so careless. It will be desired (suggested, decided, orde
36、red, requested, proposed, etc.) that she should finish her homework this afternoon.a在上述三种主语从句中,should意为应该、竟然,可以省去,但不可换用would。主句所用动词的时态不限。注意：这种从句表示的是事实。如果说话人对这种事实表示惊奇,就可用虚拟语气。反之，如果不表示惊奇，that从句也可用陈述语气。例如:It is strange that he did not come yesterday. It is a pity that you cant swim.四、虚拟语气用于表语从句、同位语从句要求
37、：demand requirement request motion pray insistence 建议：suggestion advice proposal recommendation motion命令、决定：order command decision determination resolution其它：plan desire idea necessity preference等名词的表语从句和同位语从句,其谓语动词要用虚拟语气的结构(should)+动词原形。例如:We all agreed to his suggestion that we(should)go to Beijin
38、g for sightseeing. My idea is that he (should)do exercises first.五、虚拟语气的几种特殊用法7. 省掉if的条件从句倒装结构：(should, had, were)Had you asked me, I would have told you. (=If you had asked me,)Were I you, I would be back home. (= If I were you, )Should I know it, I would tell you. (= If I should know it, )8. 有时虚拟条
39、件不用条件从句而用不定式、分词、介词、名词、连接词或定语从句来表示，如：Atrue friend would not do such a thing. (=If he were a true friend, he.) Without water, we would not live. (=If there were no water,) But for your help, I couldnt have finished it.(=If you hadnt helped me,)9. 虚拟语气用于定语从句:Its (high) time that+动词过去式或should+动词原形， (sho
40、uld不能省略,be用were)来表示,意为(现在)该。如：Its time (that) you had a hair cut.Its high time (that) we took some action.10. 虚拟语气用于if only引导的感叹句:If only I had taken his advice.我要是听他的话就好了。 If only I were a bird!我如果是一只鸟就好了。11. 虚拟语气用于简单句2) 表示说话人谦虚、客气、有礼貌,使语气委婉,常出现在日常会话中。例如:It would be better for you not to stay up to
41、o late. Would you be kind enough to open the door?2)用于一些习惯表达法中。例如:Would you like a cup of tea. You had better go now.3)用may+动词原形,表示祝愿、但愿。may须置于句首。例如:May you be happy!May you succeed!12. 含蓄条件句在某些虚拟语气结构中没有if条件句,虚拟条件是用其它形式表示出来,这种现象在语法上称为含蓄条件句。含蓄条件具体分为以下几种情况:7) 通过动词不定式短语表示条件。例如:You would be a fool to re
42、fuse his offer.(=If you should refuse his offer, you would be a fool.)要是你拒绝他的建议,就太傻了。8) 通过介词短语表达条件。例如:But for the storm I would have arrived much earlier.(=If it had not been for the storm.)要不是那场暴雨,我早就到达了。Without air, there would be no living things. I would not have succeeded but for your help.9) 通
43、过连词otherwise, or, but, that, though, once等表达条件。例如:She came to town yesterday, otherwise/or I would not have met her.昨天她到城里来了,不然我就不会遇见她了。(otherwise/or=if she hadnt come)I would have attended the meeting, but I have been too busy.(=.if I had not been too busy)我本来要参加会议的,只是太忙了。10) 通过Were it not for.或Had
44、 it not been for.等句式表达条件。意为如果当时没有,表示同过去事实相反的假设。例如:Were it not for(=If it were not for) the leadership of the Party, we could not live a happy life.要不是党的领导,我们不可能过幸福生活。(与现在事实相反)Had it not been for(=If it had not been for) the leadership of the Party, we should have failed.若不是有党的领导,我们早就失败了。(与过去事实相反)11)
45、 通过分词短语表达条件。例如:Given more attention, the trees could have grown better.倘若给予更多的关心,这些树本来可以生长得更好的。(=If they had been given more attention.)12) 无词句暗示条件。例如:Such mistakes could have been avoided.这种错误本来可以避免的。(暗含条件从句if we had been more careful)It was so quiet, you could have heard a pin drop.是那样的安静,掉根针你都听得见
46、。(暗含条件从句if it had dropped to the ground)Unit3It的用法一、it 作人称代词1. it的最基本用法是作代词，主要指刚提到的事物，以避免重复:Xian isabeautifulcity, isntit?2. 也可以指动物或婴儿(未知性别的婴儿或孩子):Is this your dog? No, it isnt.二、it作非人称代词 it有时并不指具体的东西，而泛指天气、时间、日期、距离、价值、度量、温度、环境等，称为非人称的it：1. 指天气： It is a lovely day, isntit? It is a bit windy.2. 指时间： It was nearly midnight when she came back.3. 指环境： It was very quiet inthecaf. 4. 指距离： It is half an hourswalkto the city centre from my home.5. 指日期： -Whats the date today? -Its May 1, 2007.6. 指季节： It is summer now.7. 指度量： It is about 5 kilograms.8. 指价值： -What
