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 If 条件从句 1).动词过去式(或were) 2).助动词（过去式）+动词原形 结果从句 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. 2. 与过去事实相反 连接词 If 条件从句 had+过去分词 结果从句 Should/Would/Could/might + have+过去分词 If I’d 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 1. should+动词原形 If 2. 动词过去式 3. were to+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 doctor's 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
1. 方式状语as if(as though)
Should/Would/could/might+动词原形 结果从句 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 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 he 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 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 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 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(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were I 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 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 they’d 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 don’t know if they can come.) （2） We wish they 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: I'd 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)
I'd rather she hadn't 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 / 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, 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 can't 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 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 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 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：A
true 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 couldn’t have finished it.(=If you hadn’t helped me,…)
3. 虚拟语气用于定语从句:It’s (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： It’s time (that) you had a hair cut.
It’s 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 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 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. 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 hadn't come) I would have attended the meeting, but I have 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)
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 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。 (暗含条件从句if it had dropped to the ground)
(=...if I had not been too busy)
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could, might等代替should, would。 5. 与现在事实相反 连接词 If 条件从句 1).动词过去式(或were) 2).助动词（过去式）+动词原形 结果从句 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 If 条件从句 had+过去分词 结果从句 Should/Would/Could/might + have+过去分词 If I’d 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 1. should+动词原形 If 2. 动词过去式 3. were to+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. 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 doctor's 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. 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 side 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\"。
Should/Would/could/might+动词原形 结果从句 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 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
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 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 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(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were I 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 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 they’d 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 don’t 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: I'd 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)
I'd rather she hadn't 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 / 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, 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 can't 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 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 Beijing 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：A
true 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 couldn’t have finished it.(=If you hadn’t helped me,…)
9. 虚拟语气用于定语从句:It’s (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： It’s time (that) you had a hair cut.
It’s 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 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 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 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。 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 hadn't come) I would have attended the meeting, but I have 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 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) 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。 (暗含条件从句if it had dropped to the ground)
(=...if I had not been too busy)
Unit3
It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: Xi’an is a beautiful city, isn’t it?
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 isn’t. 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, isn’t it? 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 in the café.
4. 指距离： It is half an hour’s walk to the city centre from my home. 5. 指日期： --What's the date today? --It's 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's the cost of the T-shirt? ----It is 150 yuan. 三、it用作形式主语
替代作主语的从句、动词不定式、动名词，而把真正作主语的从句、动词不定式、动名词置于句尾。
1. 代作主语的动词不定式 (1) It +be+ adj.+（for sb.）to do sth.
此处adj. 通常为描述事件的形容词：easy, difficult, hard, necessary, unnecessary, possible, impossible, likely, unlikely, right, wrong, important, unimportant, legal, illegal, polite, impolite, clear, obvious, certain, suitable, proper, fit, useful, useless, dangerous… It is illegal（for a teenager）to drive a car without a license. (2) It +be+ adj. of sb. to do sth.
此处adj. 通常为描述人的形容词：kind, unkind, nice, rude, cruel, considerate, thoughtful, thoughtless, careful, careless, silly, foolish, stupid, clever, wise, crazy. It's kind of you to help me with the problem. (3) It替代作主语的动名词的常见句型 It's no good/use doing… It's（well）worth doing… It's（well）worthwhile doing/ to do It's no use crying over spilt milk. 2. it作形式主语替代主语从句 ①It+ be+ adj. +clause
It is clear ( obvious, true, possible, certain …) that ...
该句型中it 是形式主语，真正的主语是that 引导的主语从句，常译为“清楚（显然, 真的……）” 是主语从句最常见的一种结构。例如： It is very clear that he’s round and tall like a tree. ②It +be +v-ed +that…=sb./sth.+be+ to do
It is said (reported/ learned/believed/thought/known/told/hoped.....) that ...
该句型中的it 仍是形式主语，真正主语是that 引导的主语从句；该结构常译为“据说（据报道，据悉. . . ）”。
It is reported that another earth satellite has been put into orbit. ③ It +be + noun +从句 It is a pity /a shame + that ...
该句型中，that后的从句一般用虚拟语气（should + 动词原形），should可省去. 表示出乎意料，常译为“竟然”。没有这种意义时，则不用虚拟语气。 It is a pity that such a thing (should) happen in your class. 这种事竟然发生在你们班上，真是遗憾！ It is a pity that he is ill. 他生病了，真遗憾！ 四、it作形式宾语
当复合宾语中的宾语是不定式、动名词宾语从句时，往往把宾语放在它的补足语后面，而用it 作形式宾语，放在宾语补足语之前。
该句型中的it 作形式宾语，常用的动词有think, believe, make, find, consider, feel等。 I think it no use arguing with him. 我认为和他争吵没有用。 I found it very interesting to study English. 我发现学英语非常有趣。 He made it clear that he was not interested in this subject. 他非常清楚地表示他对那门学科不感兴趣。 五、用于强调句型中
It is/was + 被强调部分 + that/who ... It is not until + 被强调部分 + that ... It was five o’clock _________I got home. It was at five o’clock_______ I got home.
强调句用以强调主语，宾语，介词宾语以及状语。强调人时用that和who ／whom皆可 It was she who ／that had been wrong. It was the girl whom ／that I met just now. It was Tom to whom the teacher had talked. It was on Monday night that all this happened. It is not until + 被强调部分 + that ...
该句型也是强调句型。主要用于强凋时间状语，译成汉语 “直到……才……”，可以说是not ... until ... 的强调形式。例如:
It was not until she took off her dark glasses that I realized she was a famous film star. = Not until she took off her dark glasses did I realize she was a famous film star. = I didn’t realize she was a famous film star until she took off her dark glasses. 六、It 常用的固定搭配 1. make it
（1）在口语当中相当于succeed，表示：成功、做到、说定、赶上、及时到达
It's hard to make it to the top in show business.
（2）在口语中相当于fix the date for，表示“约定好时间”例 —Shall we meet next week？ —OK. We just make it next Saturday. 2. take it/things easy
相当于Don‘t worry or don’t hurry. 用来劝告别人，表示“不要慌，别担心，沉住气” Take it easy! He will do it well.
3. It all depends/that all depends 在口语中，相当于it hasn‘t been decided yet，表示“那得看情况，还没有定下来”
—Are you going to the countryside for holiday? —It/That all depends. 4. It's up to sb.
在口语中，相当于it's decided by sb. 表示“由……决定，由……负责，取决于……” —Shall we go out for dinner? —It's up to you.
Unit4
it的用法—强调句型
一、强调句型的基本用法
英语中常用的强调句型是：It is / was + 被强调部分(主语、宾语、状语) + that / who / whom + 其他部分。一般来说，被强调部分指人时，用who或whom，其他情况用that，但that也可指人。
现在用强调句型强调下面这个句子的主语、宾语和状语。 She met John at Mary’s birthday party last Sunday.
→It was she who / that met John at Mary’s birthday party last Sunday. (强调主语) →It was John Whom / that she met at Mary’s birthday party last Sunday. (强调宾语) →It was at Mary’s birthday party that she met John last Sunday. (强调地点状语) →It was last Sunday that she met John at Mary’s birthday party. (强调时间状语) 温馨提示：
1.it为引导词，本身没有词义，仅起引导强调句式的作用；
2.若强调的主语是人时，常用who，间或用that，若强调的宾语是人时，多用whom / that； 3.在强调状语时，用that；
4.在强调结构时，无论被强调的是人还是物，是单数还是复数，be动词一律用单数形式is / was,
如果原句中的谓语动词是过去时态，就用was，若是现在时态或将来时态，就用is， 也可用情态动词 + be形式；
5. 判断一个句子是否是强调句型的方法：如果将句中的It is / was… that / who / whom…去掉，仍能还原为一个完整的句子，那么此句就是强调句。否则，就是其他句型结构。 请比较： It was 1999 when he came back from the United States. (定语从句)
It was in 1999 that he came back from the United States. (强调句型)
6. 被强调部分若是句子的主语，that / who之后的谓语动词在人称和数上应与句子的主语保持一致。
eg：It is I that / who am your friend that will come to help you. 二、强调句型的几种较为复杂的结构形式 1. 被强调部分为状语从句。
Eg: It was when Tom was eleven years old that his talent for writing became obvious. 2. 被强调部分含有定语从句。
Eg: It was on July 4 th, 1975 when he was born that his father died. 3. not…until结构用于强调句型。
not…until作为被强调部分，起结构是：It is / was + not until…+ that + 其他部分。 Eg: It was not until his father came back that he went to bed. 4. 强调句型的一般疑问句结构：Is / Was it + 被强调部分+ that + 其他部分。 Eg: Was it last year that his cousin joined the army? 5. 强调句型的特殊疑问句结构：疑问词（被强调部分）+ is / was + it + that + 其他部分。 Eg: When was it that the accident happened? Where was it that you lost your wallet? Unit5
一、定义：非谓语动词是在句子中充当除谓语以外的句子成分的动词形式
在句中可起名词,形容词,副词的作用,在句中充当主语,宾语,表语,补语,定语或状语.即动词的非谓语形式除了不能独立作谓语外,可以承担句子的任何成分 3种形式：不定式，分词（现在分词、过去分词），动名词 二、非谓语动词用法：
（一）动词不定式：（to）+do，具有名词、形容词、副词的特征。 1. 不定式的形式：（以动词write为例） 否定式：not + (to) do
（1）一般式：不定式的一般式所表示的动作与谓语动词动作同时发生或发生在谓语动词动作之后，例如：
I'm glad to meet you. He seems to know a lot. We plan to pay a visit. He wants to be an artist.
The patient asked to be operated on at once. The teacher ordered the work to be done.
（2）进行式：不定式的进行式所表示的动作与谓语动词动作同时发生，例如： The boy pretended to be working hard. He seems to be reading in his room.
（3）完成式：不定式的完成式表示的动作发生在谓语动词动作之前，例如： I regretted to have told a lie. I happened to have seen the film. He is pleased to have met his friend. 2. 不定式的句法功能： （1）作主语：
To finish the work in ten minutes is very hard. To lose your heart means failure.
动词不定式短语作主语时，常用it作形式主语，真正的主语不定式置于句后，例如上面两句可用如下形式：
It is very hard to finish the work in ten minutes. It means failure to lose your heart. 常用句式有： 1. It+be+名词+to do
2. It takes sb. +some time +to do 3. It+be+形容词+for sb. +to do
常用careless,,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise,等表示赞扬或批评的形容词，不定式前的sb.可作其逻辑主语。 （2）作表语：
Her job is to clean the hall. He appears to have caught a cold. （3）作宾语：
常与不定式做宾语连用的动词有：want, hope, wish, offer, fail, plan, learn, pretend, refuse, manage, help, agree, promise, prefer, 如果不定式（宾语）后面有宾语补足语，则用it作形式宾语，真正的宾语（不定式）后置，放在宾语补足语后面，例如： Marx found it important to study the situation in Russia.
动词不定式前有时可与疑问词连用，如： He gave us some advice on how to learn English. （4）作宾语补足语：
在复合宾语中，动词不定式可充当宾语补足语，如下动词常跟这种复合宾语：want, wish, ask, tell, order, beg, permit, help, advise, persuade, allow, prepare, cause, force, call on, wait for, invite.
此外，介词有时也与这种复合宾语连用，如： With a lot of work to do, he didn't go to the cinema.
有些动词如make, let, see, watch, hear, feel, have等与不带有to的不定式连用，但改为被动语态时，不定式要加to, 如： I saw him cross the road. He was seen to cross the road. （5）作定语：
动词不定式作定语，放在所修饰的名词或代词后。与所修饰名词有如下关系： ①动宾关系：
I have a meeting to attend.
注意：不定式为不及物动词时，所修饰的名词如果是地点、工具等，应有必要的介词，如： He found a good house to live in. The child has nothing to worry about. What did you open it with?
如果不定式修饰time, place, way，可以省略介词： He has no place to live.
This is the best way to work out this problem.
如果不定式所修饰名词是不定式动作承受者，不定式可用主动式也可用被动式： Have you got anything to send? Have you got anything to be sent? ②说明所修饰名词的内容：
We have made a plan to finish the work.
③被修饰名词是不定式逻辑主语（主谓关系）： He is the first to get here. （6）作状语： ①表目的：
He worked day and night to get the money. She sold her hair to buy the watch chain.
注意不定式放句首时，逻辑主语与句子主语要一致：
wrong：To save money, every means has been tried. right：To save money, he has tried every means. wrong：To learn English well, a dictionary is needed. right：To learn English well, he needs a dictionary. ②表结果：
He arrived late to find the train gone. 常用only放在不定式前表示强调： I visited him only to find him out. ③表原因：
They were very sad to hear the news. ④表程度：
It's too dark for us to see anything. The question is simple for him to answer. （7）不定式的省略：保留to省略do动词。 If you don't want to do it, you don't need to. （8）不定式的并列：第二个不定式可省略to。 He wished to study medicine and become a doctor. （二）动名词：
动名词既具有动词的一些特征，又具有名词的句法功能。 1. 动名词的形式： 否定式：not + 动名词 （1）一般式：
Seeing is believing. 眼见为实。 （2）被动式：
He came to the party without being invited. 他未被邀请就来到了晚会。 （3）完成式：
We remembered having seen the film. 我们记得看过这部电影。 （4）完成被动式：
He forgot having been taken to Guangzhou when he was five years old. 他忘记五岁时曾被带到广州去过。 （5）否定式：not + 动名词
I regret not following his advice. 我后悔没听他的劝告。 （6）复合结构：物主代词（或名词所有格）+ 动名词 He suggested our trying it once again. 他建议我们再试一次。 His not knowing English troubled him a lot.
他不懂英语给他带来许多麻烦。 2. 动名词的句法功能： （1）作主语：
Reading aloud is very helpful. 朗读是很有好处的。 Collecting stamps is interesting. 集邮很有趣。 当动名词短语作主语时常用it作形式主语。 It's no use quarrelling.争吵是没用的。 （2）作表语：
In the ant city, the queen's job is laying eggs. 在蚂蚁王国，蚁后的工作是产卵。 （3）作宾语：
They haven't finished building the dam. 他们还没有建好大坝。 We have to prevent the air from being polluted. 我们必须阻止空气被污染。
注意动名词既可作动词宾语也可作介词宾语，如上面两个例句。此外，动名词作宾语时，若跟有宾语补足语，则常用形式宾语it，例如：
We found it no good making fun of others. 我们发现取笑他人不好。 要记住如下动词及短语只跟动名词作宾语：
enjoy, finish, suggest, avoid（避免）, excuse ,delay, imagine, keep, miss, consider, admit（承认），deny（否认）, mind, permit, forbid, practise, risk（冒险）, appreciate（感激）, be busy, be worth, feel like, can't stand, can't help（情不自禁地）, think of, dream of, be fond of,
prevent…(from),keep …from, stop…（from）,protect…from, set about, be engaged in, spend…(in), succeed in, be used to, look forward to, object to, pay attention to, insist on, feel like （4）作定语：
He can't walk without a walking-stick. 他没有拐杖不能走路。 Is there a swimming pool in your school? 你们学校有游泳池吗？ （5）作同位语：
The cave, his hiding-place is secret. 那个山洞，他藏身的地方很秘密。 His habit, listening to the news on the radio remains unchanged. 他收听收音机新闻节目的习惯仍未改变。 （三）现在分词：
现在分词既具有动词的一些特征，又具有形容词和副词的句法功能。 1、现在分词的形式： 否定式：not + 现在分词
（1）现在分词的主动语态：现在分词主动语态的一般式表示与谓语动词所表示的动作同时
发生，完成式表示的动作在谓语动词所表示的动作之前发生，常作状语。例如： They went to the park, singing and talking. 他们边唱边说向公园走去。 Having done his homework, he played basket-ball. 做完作业，他开始打篮球。
（2）现在分词的被动语态：一般式表示与谓语动词同时发生的被动的动作，完成式表示发生在谓语动词之前的被动的动作。
The problem being discussed is very important. 正在被讨论的问题很重要。 Having been told many times, the naughty boy made the same mistake. 被告诉了好几遍，这个淘气的孩子又犯了同一个错误。 2. 现在分词的句法功能：
（1）作定语：现在分词作定语，当分词单独做定语时，放在所修饰的名词前；如果是分词短语做定语放在名词后。
In the following years he worked even harder. 在后来的几年中，他学习更努力了。
The man speaking to the teacher is our monitor's father. 正与老师谈话的那个人是我们班长的父亲。
现在分词作定语相当于一个定语从句的句法功能，如：in the following years也可用in the years that followed; the man speaking to the teacher可改为the man who is speaking to the teacher.
（2）现在分词作表语：
The film being shown in the cinema is exciting. 正在这家上演的电影很棒。 The present situation is inspiring. 当前的形势鼓舞人心。 （3）作宾语补足语：
如下动词后可跟现在分词作宾语补足语：
see, watch, hear, feel, find, get, keep, notice, observe, listen to, look at, leave, catch等。例如： Can you hear her singing the song in the next room? 你能听见她在隔壁唱歌吗？ He kept the car waiting at the gate. 他让小汽车在门口等着。 （4）现在分词作状语： ①作时间状语：
(While) Working in the factory, he was an advanced worker. 在工厂工作时，他是一名先进工人。 ②作原因状语：
Being a League member, he is always helping others. 由于是共青团员，他经常帮助他人。 ③作方式状语，表示伴随：
He stayed at home, cleaning and washing. 他呆在家里，又擦又洗。 ④作条件状语：
(If) Playing all day, you will waste your valuable time. 要是整天玩，你就会浪费宝贵的时间。 ⑤作结果状语：
He dropped the glass, breaking it into pieces. 他把杯子掉了，结果摔得粉碎。 ⑥作目的状语：
He went swimming the other day. 几天前他去游泳了。 ⑦作让步状语：
Though raining heavily, it cleared up very soon. 虽然雨下得很大，但不久天就晴了。 （四）过去分词：
过去分词只有一种形式：规则动词由动词原形加词尾-ed构成。不规则动词的过去分词没有统一的规则要求，要一一记住。 过去分词的句法功能： 1. 过去分词作定语：
Our class went on an organized trip last Monday. 上周一我们班开展了一次有组织的旅行。 Those elected as committee members will attend the meeting. 当选为委员的人将出席这次会。 注意当过去分词是单词时，一般用于名词前，如果是过去分词短语，就放在名词的后面。过去分词做定语相当于一个被动语态的定语从句。 2. 过去分词作表语：
The window is broken. 窗户破了。
They were frightened at the sad sight. 他们对眼前悲惨的景象感到很害怕。 有些过去分词是不及物动词构成的，不表示被动，只表示完成。如： boiled water（开水） fallen leaves（落叶）
newly arrived goods（新到的货） the risen sun（升起的太阳） the changed world（变了的世界）
这类过去分词有：gone, come, fallen, risen, changed, arrived, returned, passed等。 3. 过去分词作宾语补足语：
I heard the song sung several times last week. 上周我听见这首歌被唱了好几次。
有时过去分词做with短语中的宾语补足语：
With the work done, they went out to play. 工作做完了，他们出去玩去了。 4. 过去分词作状语：
Praised by the neighbours, he became the pride of his parents. 受到邻居们的表扬，他成为父母的骄傲。（表示原因） Once seen, it can never be forgotten.
一旦它被看见，人们就忘不了。（表示时间） Given more time, I'll be able to do it better.
如果给予更多的时间，我能做得更好。（表示条件） Though told of the danger, he still risked his life to save the boy. 虽然被告之有危险，他仍然冒生命危险去救那个孩子。（表示让步）
Filled with hopes and fears, he entered the cave. 心中充满了希望与恐惧，他走进山洞。
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