it的全部用法

it既可作人称代词，用来表示动物或无生命的物体等，也可以作无人称代词，在句中作主语，表示“时间”、“距离”、“天气”等。它还可以引导强调句，使语气得以加强。此外，it在句中能作引导词，充当句子中的形式上的成分，如形式主语、形式宾语等。

㈠ it作形式主语：
it作形式主语时没有具体的意义，而只是帮助把真正的主语移到句子后部去，使句子显得平稳一些。it作形式主语时，可以代替三种形式：

不定式、动名词和主语从句。

⒈ it代替不定式短语
常用于下列句型中：
It + be +形容词 + (for/of sb.) to do sth.
It + be + 名词 + to do sth.
It takes sb. some time to do sth. 干…花了某人…时间
It’s up to sb. to do sth. 干…是某人的职责或义务

如：
①It is everyone’s duty to obey the law.
遵守法律是每个人的义务。
（ it作形式主语, 代替不定式短语to obey the law）

②It is difficult for a foreigner to learn Chinese.
对于一个外国人来说，学习汉语是困难的。
（ it作形式主语, 代替不定式短语to learn Chinese）

③It is not right to use these places as rubbish dumps.
把这些地方用来倒垃圾是不对的。
（it作形式主语, 代替不定式短语to use these places as rubbish dumps）

④It took them a year to build the bridge.
建这座桥花了他们一年的时间。
（ it作形式主语, 代替不定式短语to build the bridge）

⑤It is bad manners to stare at people.
瞪着眼睛看人是不礼貌的。
（ it作形式主语, 代替不定式短语to stare at people）

⑥It is up to us to help those in need.
帮助那些有困难的人是我们的责任。
（ it作形式主语, 代替不定式短语to help those in need）

⑦It is not up to you to tell me how to do my job.
我怎样干我的工作不用你来多嘴。
（ it作形式主语, 代替不定式短语to tell me how to do my job）

◆ It be + 形容词+ for sb. to do sth.与It be + 形容词+of sb. to do sth.：
如果句型中的形容词描述的是sb.的品质、品格，在逻辑上可以作sb.的表语，则sb.前应用介词of，否则就用for。
如：
①It’s necessary for us to use a short-wave radio to pick up the programmes.
我们用一台短波收音机收听这些节目是必要的。

②It’s important for us to learn English well.
学好英语对我们来说是重要的。

③It’s kind of you to help me.
感谢你对我的帮助。（= You are kind to help me. ）

④It was foolish of him to give up the job.
他放弃那工作是愚蠢的。（= He was foolish to give up the job.

）

⒉ it代替动名词短语：
动名词作主语用后置形式的情况远不及不定式那么普遍，常限于no good, no use, useless, waste等词的后面。
①It is no good/ use having a car if you can’t drive.
如果你不会开车，有车也没用。
( it作形式主语,代替动名词短语having a car)

②It is a waste of time watching TV.
看电视是浪费时间。
（ it作形式主语,代替动名词短语watching TV）

③It is no use asking him.
问他没有用。
（ it作形式主语,代替动名词短语asking him）

④It is no use talking to him about it.
和他谈这事没有用。
（ it作形式主语,代替动名词短语talking to him about it）

⒊ it代替主语从句：
这个主语从句可以用连词that引导，也可以用连接代词或连接副词引导。
如：
①It was clear that they had no desire for peace.
很清楚他们没有和平的诚意。
（ it作形式主语,代替主语从句that they had no desire for peace）

②It is doubtful whether she will be able to come.
她能否来还很难说。
（ it作形式主语,代替主语从句whether she will be able to come）

③It was clear enough what she meant.
她的意思是够清楚的。
（ it作形式主语,代替主语从句what she meant）

④It hasn’t been made clear when the new road is to be opened to traffic.
还没明确宣布新路什么时候通车。
（ it作形式主语,代替主语从句when the new road is to be opened to traffic）

⑤It is a mystery to me how it all happened.
这都是怎么发生的对于我来说还是一个谜。
（ it作形式主语,代替主语从句how it all happened）

用it作形式主语，把真正的主语从句移至后面的常见句型有：
◆ It is a pity/ a shame/ a fact/ an honour/ good news/ no wonder/ a wonder… that…
如：
①It was a pity that the engineer couldn’t come.
可惜工程师没能够来。

②It is a wonder that he continues to gamble when he always loses!
令人惊讶的是他一直输还一直赌。

③（It is）no wonder (that) you were late!
难怪你来晚了。

④It is a shame that the rain spoiled our picnic.
真可惜，这场雨把我们的野餐给搅了。

⑤It is a fact that English is being accepted as international language.
英语被认为是国际语言，这是一个事实。

◆ It is + 形容词（如： strange/ natural/ surprising/ obvious/ true/ fortunate/ wonderful/ funny/ possible/ impossible/ likely/ unlikely/ clear/ unusual/ certain/ important…）that …
如：
①It is certain that he will win.
他一定会取胜。

②It is important that we shou

ld learn from each other and help each other.
我们应当互相学习，互相帮助，这是很重要的。

③It was obvious that the child had been badly treated.
很显然那个孩子受过虐待。

④It is likely that he will ring me tonight.
他今晚可能给我打电话。

⑤It is strange that he should have left without telling us.
真奇怪，他也没说一声就走了。

⑥It is unlikely that their group will get ahead of us.
他们小组不会赶到我们前头去。

◆ It seems/ happened/ turned out/ suddenly struck me/ occurred to me…that …
如：
①It happened that I wasn’t there that day.
恰好那天我不在那里。

②It seems that his idea is more practical.
看起来他的意见更实际一些。

③It suddenly occurred to me that I knew how to solve that problem.
我忽然想起我知道怎样解决那个问题。

◆ It + be + 过去分词（如：said/ reported/ announced/ decided/ expected/ hoped/ known/ believed…）that…
如：
①It is hoped that the number of deer will greatly increase very soon.
(相当于：People hope that the number of deer will greatly increase very soon)
人们希望鹿的数目将会很快增加。

②It is said that nothing has been done about it.
据说至今对此没采取任何措施。

③It is reported that more than twenty people were killed in that bus accident.
据报道在那次的公共汽车事故中有二十多人丧生。

④It is known that he is one of the best teachers in our school.
大家都知道他是我们学校最好的教师之一。

⑤It is believed that the flood there is the biggest in 100 years.
据认为那儿的洪水是百年来最大的洪水。

* 注意要在It is suggested/required/desired/ordered/proposed…that…的主语从句中用虚拟语气：
(should) + 动词原形
如：
①It is requested that he give a performance at the party.
有人请求他在聚会上表演一个节目。

②It is suggested that we should get everything ready by tonight.
建议一切在今晚准备好。

③It is ordered that the radio be sent there at once.
据命令，这台收音机要立刻送到那里去。

◆ It doesn’t matter +连接代词或副词…
It doesn’t make too much difference +连接代词或副词…
如：
①It doesn’t matter whether he comes or not.
他来还是不来都没关系。

②It won’t make much difference whether you go today or tomorrow.
你今天去也好，明天去也好，关系不大。

㈡ it作形式宾语：
it作形式宾语时，可以代替三种形式：
不定式、动名词和宾语从句。
it作形式宾语时

，需具备两个条件：
① 真正的宾语是不定式、动名词或从句
② 有宾语补足语
具备了这两个条件，形式宾语it一定要用。

⒈ it代替不定式短语
think/ find/ feel/ consider/ make/ regard…+ it +形容词/名词 + 不定式短语
如：
①I find it pleasant to work with him.
(it 作形式宾语，代替不定式短语to work with him)
我觉得和他一起工作很愉快。

②They felt it difficult to finish the work in such a short time.
（ it 作形式宾语，代替不定式短语to finish the work in such a short time）
他们认为在这么短的时间内完成这项工作是困难的。

③She thinks it her duty to help us.
（ it 作形式宾语，代替不定式短语to help us）
她觉得帮助我们是她的责任。

④I think it my honor to be invited to speak here.
（ it 作形式宾语，代替不定式短语to be invited to speak here）
我觉得应邀在这儿演讲是我的荣耀。

⑤Tom didn’t find it difficult to write letters in Chinese.
（ it 作形式宾语，代替不定式短语to write letters in Chinese）
汤姆发现用汉语写信不难。

⑥All these noises made it impossible for me to go on with the work.
（ it 作形式宾语，代替不定式短语to go on with the work）
这些噪音使我无法继续工作。

⒉ it代替动名词短语( 这只限于少数句型，在多数情况下用不定式时更多一些)
如：
①The professor considers it no good reading without understanding.
这位教授认为阅读而不理解没有益处。

②Do you consider it any good trying again?
你觉得再试会有好处吗？

③He found it useless( no use) arguing with him.
他发现和他辩论没有用。

④He thought it absolutely senseless attempting the impossible.
想做不可能的事情，他认为是完全没道理的。

⑤I don’t think it worthwhile going to such a place.
到这样一个地方去我看是不值得的。

⒊ it代替宾语从句：
如：
①We all thought it a pity that the conference should have been cancelled.
会议取消了我们都感到很遗憾。

②I took it for granted that they were not coming.
我想他们准是不会来的了。

③I’ll see to it that everything is ready in time.
我负责使一切都按时准备好。

㈢ 含it 的常用句型
英语中有一些固定句型中含有it,应注意这些句型的使用。

⒈ It be + 被强调部分 + that/ who + 其他成分
强调句型可以强调一个句子的主语、宾语、表语及状语等成分。如果被强调的成分是表示人的词，可以用that或who(whom)连接其他成分；被强调的成

分是表示人以外的词，例如表示事物、时间或地点的词，用that连接其他成分。例如我们可以用强调句型强调下列句子的主语（如⑴　）、宾语（如⑵　）、地点状语（如⑶　）及时间状语（如⑷　）

I met Peter in Japan last year.
⑴ It was I who/that met Peter in Japan last year.
⑵ It was Peter whom/that I met in Japan last year.
⑶ It was in Japan that I met Peter last year.
⑷ It was last year that I met Peter in Japan.

* not …until 也可用于强调句型
例１　Mr Brown didn’t come back until eleven o’clock.
可变为：It was not until eleven o’clock that　Mr Brown came back.

例2 The rain didn’t stop until midnight.
可变为：It was not until midnight that the rain stopped.

* 强调句也可变为特殊疑问句
例１　It was in 1949 that the PRC was founded.
可变为：When was it that the PRC was founded?

例2 Your dad worked in this factory two years ago.
可变为：Where was it that your dad worked two years ago?

⒉
It’s + 地点状语+ that… （强调句）
It’s +地点名词+ where… (定语从句)
如：
①It is the town where I was born.
(the town 为地点名词，定语从句)
这是我出生的镇子。

②It was in the town that I was born.
(in the town为地点状语，强调句型)
我出生在这个镇子。

⒊
It’s + 时间名词+ when…(时间状语从句)
It’s + 时间状语 +that…(强调句)
如：
①It was at 8 o’clock that he returned.
(at 8 o’clock是时间状语，强调句)
他是在八点钟回来的。

②It was 8 o’clock when he returned.
(8 o’clock 是时间名词，时间状语从句)
他回来的时候是八点钟。

⒋ if it is convenient to you 如果你方便的话
如：
If it is convenient to you, you can start tomorrow.
如果方便的话，你明天可以动身。

⒌ believe it or not 信不信由你
如：
①Believe it or not, I’ll go abroad next month.
不管你信还是不信，我下个月要出国。

②Believer it or not, we were left waiting in the rain for two hours.
信不信由你，我们冒雨一直等了两个小时。

⒍ It’s time that…did / should do …(定语从句)
如：
①It is time that I went and picked up my daughter from school.
我该去学校接我女儿放学了。

②It’s high time that we stopped/should stop this practice.
我们的确该停止这种做法了。

⒎ It is /has been…since…did…(时间状语从句)
如：
It is just a week since we arrived here.
我们来这里已一星期了。

⒏

It won’t be …before…用不了（多长时间）就会…
It will be…before…得过（多长时间）才…
It wasn’t …before…没过（多长时间）就…
It was…before…过了（多长时间）才…

如：
①It will be a long time before we finish the task.
我们还需要很长时间才能完成这项任务。

②It wasn’t long before he learned to use the computer.
不久他就学会使用计算机了。

③It was some time before he told me about this affair.
过了一段时间之后他告诉了我这件事。

④It won’t be long before we meet again.
不久之后我们还会再见面的。

㈣ 易混用其他句型
英语中有一些句型不含it, 但却易被误用了it，常见的有以下句型：
⒈ There is something/nothing wrong/ the matter with sb./ sth.
如：
There is nothing wrong /the matter with him. He’s just pretending.
他没什么事，他只是在装呢。

⒉
There is no doubt about…对…毫不怀疑
There is no doubt that…对…毫不怀疑
如：
①There is no doubt about his suitability for the job.
毫无疑问，他适合这个工作。

②There is no doubt about the fact.
关于这个事实毫无怀疑。

③There is no doubt that he is hard to deal with.
毫无置疑他很难对付。

⒊ There is no need (for sb.) to do sth. 没必要…
如：
①There was no need for him to remain in Paris.
他没有必要继续留在巴黎。

②There is no need for you to start yet.
你现在还不必动身。

⒋
There is no/a possibility that… …没可能/有可能
(= It is impossible/possible that …)
如：
①There is a possibility that the train may be late.
可能火车要晚点。

②There is no possibility that we’ll see him this weekend.
我们本周末不可能见到他。

⒌ There is a chance that …可能…
如：
There is a chance that the sick child will get well.
这个生病的孩子可能会好起来的。

⒍ There be no/ some differences between…and……和…之间没/有区别
如：
There are some differences between the two languages.
这两种语言之间有些区别。

⒎ After what seemed + 时间
如：
After what seemed a very long time, the wounded soldier came back to life.
在经过似乎很长的一段时间之后，那个受伤的士兵苏醒了过来。

⒏ There be difficulty/ trouble (in) doing sth. 干…有困难
如：
There was no difficulty in finding him.
找到他没费什么事。

高考预测题：
1.______ is reported that he got seven gold medals.
A. That B. W

ord C. It D. News

2.How long ______ to finish the work?
A. you will take B. will you take C. you will take it D. will it take you

3.__________ no need for us to discuss the problem again. It has already been settled.
A. It has B. There has C. It is D. There is

4.I was disappointed with the play. I had expected _____ to be much better.
A. that B. this C. one D. it

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

6.Does _______ matter if he can’t finish the job on time?
A. this B. it C. he D. that

7.----Do you need my ruler?
----No, thanks. I’ve got _______ myself.
A. it B. each C. one D. the one

8.----Which person do you mean?
----______ who wears a new gold watch.
A. The one B. One C. Each D. It

9.It ______ three years since I left England.
A. has been B. was C. had been D. will be

10.It won’t be long _____ the island ________ to our motherland.
A. when, returns B. before, will return C. since, returns D. before, returns

11.How many years is it ______ your family moved here?
A. after B. since C. before D. until

12.________ is a pity that you forgot both her address and her telephone number.
A. It B. There C. This D. That

13.I saw no more than one copy left in the bookshop. Will you go and buy ______?
A. it B. some C. any D. one

14.Will you see to ______ that the luggage is brought back?
A. me B. yourself C. it D. them

15.It _______ that she has lost interest in studying English.
A. seemed B. appears C. looks D. remains

16._______ happened that I met one of my friends yesterday.
A. I B. That C. It D. How

17.I think _______ right that you didn’t tell him the bad news.
A. it B. its C. you D. that

18. _______ to say which one I should choose.
A. That’s hard B. It is hard C. There no use D. It no good

19._______ surprised me most was that she had become a famous singer.
A. That B. It C. What D. This

20.______ will take you a lot of time to find him in the crowd.
A. It

B. I C. We D. They

21.He felt ______ to work for human rights and progress.
A. it his duty B. his duty C. that is a duty D. that is his duty

22.People in the west makes ______ a rule to buy Christmas presents for their relatives and friends.
A. that B. it C. this D. The thing

23.________needs further discussion whether we’ll build a library or not.
A. We B. He C. It D. The thing

24._______ is no good _______ without doing anything.
A. This, talking B. It, to talk C. It, talking D. That, to talk

25.________ is no difference between them.
A. There B. Where C. It D. What

26.Was it _______ that they saw?
A. she B. that she C. her D. herself

27._______ being Sunday, the library was closed.
A. That B. It is C. It D. This

28.It was evening _______ we arrived there.
A. that B. when C. this D. since

29.It was in the village ______ now is a small town ________ the earthquake occurred.
A. where, which B. which, where C. which, that D. that, where

30.----Few children are as bright as he is, and also, he works very hard.
----It’s no ______ that he always gets the first place in any examination.
A. question B. doubt C. problem D. wonder

答案与提示：
1.C　it在此句中是形式主语，真正的主语是that从句。这个句型的结构是：it be +过去分词 +that 从句。

2.D　it takes sb. some time to do sth. 意为“花费时间做某事”。It是形式主语，代替不定式短语。此句是将来时态。

3.D　本题用的是there be句型。There is no need to…是这个句型的一种表达方式，意思是“没有必要…”。

4.D　I had expected的宾语是前面所提到的play。英语中，通常用it 和one来替代前面单数名词，可以选C或D， one所代替的是同类事物中“一个”，而it所代替的是前面提到过的同一事物，所以答案为D。

5.A　to master a foreign language without much memory work是动词不定式短语作think的宾语。当句子的宾语是动词不定式或that从句时，我们通常用it作形式宾语，但是如果宾语不与形容词在一起，一般不能用it作形式宾语。

6.B　本题是一般疑问句。matter(有关系，要紧)经常用于否定句和疑问句，常用句型是：Does it matter…? It doesn’t matter…。

7.C　不定代词one常用

来代替与前面已提到的一个事物（人或东西），以避免重复。one表示同类事物中的“任一个”，即：表示泛指，而the one则表示确指。人称代词it被用来代替前面提到的那个东西。不定代词each常表示“每一个”的意思。根据题意（你要用我的尺子吗？不，谢谢。我自己有一支。）和结构，应选C。

8.A　不定代词one 和the one都可以被用来代替前面提到过的一个同类事物（人或东西），以避免重复。one 表示泛指，而the one表示确指。题意为：“你指的是哪个人？”“那位戴一只新金表的。”

9.A　It is /has been…since…did…(时间状语从句) 意思为：自从…以来已有…时间了。

10.D　It won’t be …before…“用不了（多长时间）就会…”，其中before引导的是时间状语从句，所以应用现在时态。

11.B　It is /has been…since…did…(时间状语从句) 意思为：自从…以来已有…时间了。题意为：你们家搬到这里已多长时间了？

12.A　It is a pity that…其中it是形式主语，that从句是真正的主语。

13.A　one表示同类事物中的“任一个”，即：表示泛指。人称代词it被用来代替前面提到的那个东西。no more than 表示“仅仅，只有”。

14.C　it 作形式宾语，真正的宾语是后面的that 从句。

15.B　it seems/appears that…为固定句型，“似乎…”。选项A的时态不对。

16.C　it happened that…为固定句型，意思是“碰巧…”。题意为：昨天我碰巧碰到了我一位朋友。

17.A　it 作形式宾语，真正的宾语是 “that you didn’t tell him the bad news”

18.B　it 作形式主语，后面的不定式短语作真正的主语。

19.C　what surprised me most 在本题中是主语从句。如果选B, 则应把原题中的was去掉，变为：It surprised me most that she had become a famous singer. (it 做形式主语)

20.A　本题用的是句型：It takes sb. some time to do sth. 干…花了某人…时间。其中it作形式主语。

21.A　feel/ find/ think / consider/ make/ regard…+ it +名词/ 形容词 +不定式短语, 其中it做形式宾语，真正的宾语是“to work for human rights and progress”

22.B　make / find/ think / consider/ feel / regard…+ it +名词/ 形容词 +不定式短语, 其中it做形式宾语，真正的宾 语是“to buy Christmas presents for their relatives and friends”

23.C　it作形式主语，真正的主语是后面的从句“whether we’ll build a library or not”

24.C　本题用的是句型：It is no good doing sth. 意思是“干…没用/好处” 其中it 作形式主语，用来代替后面的动名词短语。

25.A　本题用的是固定句型：There is no difference between…意思

是“和…之间没/有区别”，注意别误选it。

26.C　本题为一个由强调句变成的一般疑问句，被强调的人称代词为宾格。原句应为：They saw her. 选项B的句子结构语法不对。

27.C　It being Sunday是独立主格结构，在此相当于原因状语从句。it在此题中表示时间。

28.B　It’s + 时间名词+ when…；It’s + 时间状语 +that… 这是一个强调句。本题中的evening为时间名词，所以应选B。

29.C　本题第一个空填which, 引导的是一个定语从句，修饰先行词the village。第二个空是强调句，所以选that，“是在这个村庄发生了地震”。

30.D　It’s no wonder that…为固定句型，意思是“难怪…”。