it作形式主语和形式宾语的用法

　　it作形式主语和形式宾语的用法

　　一、It用作形式主语

　　当不定式(短语)、动名词(短语)或从句在某个句子中作主语时，为保持句子结构前后平衡，避免头重脚轻，因此常用it作形式主语置于句首，而将真正的主语放在句尾。此时it只起先行引导作用，本身无词义。

　　It作形式主语的常见句型：

　　1.It + be +形容词+ to dosth. / doing / that….(常见的形容词有clear/obvious/true/possible/certain……)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，肯定……)”是主语从句最常见的一种结构。

　　e.g. It is very important to learn a foreign language.(学一门外语非常重要。)

　　It is very clear that he's round and tall like a tree.

　　It is useless crying over the spilt milk.(覆水难收。)

　　It was really surprising that she married a man like that.

　　(她嫁给那样的男士真让人惊讶。)

　　2.Itis kind ( of sb. ) to dosth.该句型中的不定式短语是真正主语，如果不定式的逻辑主语是由of引起，主句中的形容词必须是能表示逻辑主语特征的形容词。常见的有: bad, brave, careless, clever, cruel, foolish, good (好心的), honest, horrible, kind, lazy, modest, naughty, nice (有教养的), polite, rude, silly, stupid, wise, wrong (错误的)等。这个句型可以改写为：sb. is kind to dosth.

　　It is kind of you to say so. = You are kind to say so.

　　3.It + be +名词词组(no good/no use/a pity/a truth……)+ doing / that….

　　e.g. It is no good telling lies.(撒谎没好处。)

　　It is a pity that you didn’t go to see the film yesterday.

　　(你昨天没看成那部电影真遗憾。)

　　It is a truth that there would be no new China without the Communist Party.

　　(没有共产党就没有新中国，这是毋庸质疑的。)

　　4.it is good /better manners to dosth做什么事有礼貌

　　It good manners to say Hello to others in the street.

　　5.It + be +过去分词+ that….

　　Itbe suggested that +sb+should +v

　　该句型常见动词有：say, hope, think, suppose, expect, report, know, believe, decide, etc.

　　e.g. It is said that they have invented a new type of computer.

　　(据说他们发明了一种新型电脑。)

　　It is believed that China will become one of the strongest countries in the world.

　　(大家都相信中国将会步入世界强国之列。)

　　It was reported that more than 170 thousand people died in the 2004 tsunami.

　　(据报道，至少有十七万人在2004年那场海啸中丧生。)

　　6.It + seems / appears / happens等不及物动词+ that…

　　It occurs to/ hit/strikessbthat从句(突然想起某事…)

　　e.g. It seems that he enjoys pop songs very much.

　　(似乎他非常喜欢流行歌曲。)

　　It appears that Tom might change his mind.

　　(看来汤姆可能会改变主意。)

　　7. It is important /necessary/ right/strange/natural... that ...+(should) do

　　该句型和上一个同属一个句型。由于主句中的形容词不同，that后的从句中要用虚拟语气(should +动词原形)，should可以省去。

　　It is strange that he (should) be so rude to us.

　　8.It/This/That is the first( second… ) time thatsbhas/have done…

　　It/This/That was the first( second… ) time thatsbhad done…

　　该句型要和上一个句型区别开来。该句型中的that从句不用虚拟语气，而用完成时态。至于用什么完成时态，由主句的谓语动词的时态决定。如果是一般现在时，后面从句用现在完成时态;如果是一般过去时，后面从句则用过去完成时态。该结构中that可以省去;it有时用this替换，常译为“是第一(二)……次……”。

　　It is the first time I have been here.

　　= This is the first time I have been here.

　　It was the first time I had been here.

　　9.It + takes + (sb.) + some time + to dosth.

　　这是一个表示“(某人)花多少时间干某事”的句型，其中it是形式主语，代替后面的不定式(to dosth.)，句型中的sb.也可以省略。

　　e.g. It took me some time to read the reading materials.

　　(我花了一些时间才读完那段阅读材料。)

　　It took him fourteen hours to go to New Zealand from Shanghai by plane.

　　(从上海乘飞机去新西兰花了他14小时。)

　　How long does it take you to go to Beijing from Qingdao by train?

　　(从青岛坐火车到北京一般要花多久时间?)

　　I am not sure, but I think it takes at least nine hours to get there.

　　(我不能肯定，但估计至少要九个钟头才能到那儿。)

　　10.It doesn’t matter whether/if+从句(不论(是否)……没关系……)

　　It doesn’t matter whetheryou will attend the meeting or not.

　　二、It用作形式宾语

　　当不定式(短语)、动名词(短语)或从句在某个句子中作宾语时，为保持句子结构平衡，避免句式结构的混乱，常用it作形式宾语，而将真正的宾语放在句尾。此时it仍只起先行引导作用，本身无词义。

　　下列四种情况须用it作形式宾语：

　　①当不定式(短语)、动名词(短语)或从句在复合宾语结构中作某些动词的宾语时;think/make/find/consider/feel+it+N/adj+to do/doing/that从句

　　e.g. They found it pleasant that they worked with us Chinese.

　　(他们发现与我们中国人一起工作很愉快。)

　　I don’t feel it difficult to understand the Special English.

　　(我觉得理解英语特别节目并不难。)

　　He makes it a rule never to borrow money.(他立志决不向别人借钱。)

　　I think it no need talking about it with them.(我认为没必要跟他们谈。)

　　②某些表示“喜、怒、哀、乐”的动词，如like,dislike,enjoy, love, hate，appreciate等，往往不能直接接宾语从句;

　　I will appreciate it if +从句

　　e.g.Iwill appreciate it if you could help me solve the problems.

　　I don’t like it that he’s so lazy.

　　(我不喜欢他那么懒惰。)

　　I hate it when my mother asks me to eat eggs.

　　(我讨厌母亲要我吃鸡蛋。)

　　③depend/count/rely on/ see to itthat+从句

　　owe it to you that+从句

　　take it for granted that +从句

　　e.g. You maydepend on itthat we shall always help you.

　　(尽管放心，我们会随时帮你的。)

　　Would yousee to it thatshe gets home early?

　　(你负责保证她早到家，好吗?)

　　Weowe it to youthat there wasn’t a serious accident.

　　(多亏了你才没有发生严重事故。)

　　4.IfI can help it…(如我有办法的话…)

　　Make it forget it take it

　　If I can help it, I don’t want to walk late into the night.

　　固定句型

　　1. It is/was +被强调部分+ that/who ...

　　该句型是强调句型。被强调部分可以是主语，宾语，表语或状语。强调的主语如果是人，that可以由who换用。如果把这种句型结构划掉后，应该是一个完整无缺的句子。这也是判断强调句型与其它从句的方法。

　　It was he that/who knew the fact clearly.

　　It was yesterday that he finished the work.

　　2. 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。

　　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.

　　3. It is time( abouttime , high time ) that ...

　　该句型中that后的从句应该用虚拟语气，常用过去时态表示虚拟.②有时也用should +动词原形，should不能省。常译为“是(正是)……的时侯……”。

　　It is time that you went to school.

　　4. It is …since ...

　　该句型主要用作处理瞬间动词的完成时，又要和表示一段时间的时间状语连用的问题。主句中是时间作表语，其时态是现在时或完成时，since引导的从句通常是一般过去时态，而且是瞬间动词。如果主句是一般过去时，从句则用过去完成时。

　　It is/has been ten years since you left here.

　　5.Itis…when+句子

　　It isthe cold morning when I heard the good news.

　　试比较下列高考题，选出最佳答案：

　　1. Is _______ necessary to complete the design before National Day?A. this B. that C. it D. he

　　2. I don’t think _______ possible to master a foreign language without much memory work..A. this B. that C. its D. it

　　3. Does _______ matter if he can’t finish the job on time?

　　A. this B. that C. he D. it

　　4. Tom’s mother kept telling him that he should work harder, but _______ didn’t help. A. he B. which C. she D. it

　　5. _______ is a fact that English is being accepted as an international language.

　　A. There B.ThisC.ThatD. It

　　6. I hate _______ when people talk with their mouths full.

　　A. it B. that C. these D. them

　　7. Don’t__________.A. take as granted B. take this for granted

　　C. take that for granted D. take it for granted

　　8. I like _______ in the autumn when the weather is clear and bright.

　　A. this B. that C. it D. one

　　模拟练习：

　　1. _______ happened _______ he is unfit for the office.

　　A. This; that B.That; that C.It; that D.He; that

　　2. We took _______ for granted that they would accept our advice.

　　A. that B. this C. it D. them

　　3. _______ that the scientist will give us a talk next month?

　　A. Is true B. Is it trueC.It’s true D. It’s truly

　　4. _______ doesn’t matter much _______ dress you are going to wear.

　　A. This; that B.That; who C.It; which D.It; who

　　5. _______ is going to America for further study.

　　A. He is said that B. People said that he

　　C. It was said he D. It is said that he

　　6. They are good friends. _______ is no wonder that they know each other so well.

　　A. This B.That C.There D.It

　　7. Is _______ possible to fly to the moon in a spaceship?

　　A. this B. there C. that D. it

　　8. She liked _______ when he kissed her.

　　A. him B. that C. one D. it

　　9. _______ will do you good to do some exercise every morning.

　　A. It B. There C.Those D.One

　　10. We think _______ our duty to pay taxes to our government.

　　A. that B. this C. its D. it

　　Key:高考真题: 1-8 CDDDDADC

　　模拟练习: 1-5 CCBCD 6-10 DDDAD