It-is-句型.doc

It is 句型
1. It is + 被强调部分 + that ...　 　

　 该句型是强调句型。将被强调的部分放在前面，其它部分置于that之后。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 about 600 years ago that the first clock with a face and an hour hand was made.
It was they that (who ) cleaned the classroom yesterday.
It was in the street that I met her father.

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 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，肯定．．．）＂　是主语从句最常见的一种结构。 　　

It is very clear that he’s round and tall like a tree. 　　
= That he’s round and tall like a tree is very clear.

4. It is important ( necessary, right, strange, natural...) that ...

　　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。建议记住该句型中的形容词。 　　

It is important that we (should) learn English well. 　　
It is necessary that he (should) remember these words.

5. It is said (reported, learned....) 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 said that he has come to Beijing. 　　
It is reported that another earth satellite has been put into orbit.

6. It is suggested ( ordered ... ) that ...

　　该句型和上一个同属一个句型。主句中的过去分词是表示请求，建议，命令等词时，that　后的从句要用虚拟语气（should + 动词原形），should 可以省。常译为＂据建议；有命令．．．） 　　

It is suggested that the meeting ( should ) be put off. 　
It was ordered that we ( should ) arrive there in two hours.

7. 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！

8. It is time ( about time ,high time ) that ...

　　该句型中that 后的从句应该用虚拟语气，值得注意的是① 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 children should go to bed. 　　
= It is time that children went to bed.

9. It is the first ( second ... ) time that ...

　　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.

10. 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 ) 5 years since his father died.

11. It is ... when ...

　　该句型中的 when 引导的是一个时间状语从句，主句中的 it 指时间，表语由具体的时间充当。常译为＂当．．．的时候，是．．．＂。 　　

It was 5 o’clock when he came here.

12. It be ... before ...

　　该句型主句中的 it 指时间, 主句中的时态常是将来一般时或过去时两种时态．主句中的表语多是long, not long , 3 days , 2 weeks 等表示时间段的词或短语。常译为＂．．．之后．．．＂。

It was 3 days before he went to Beijing.
It will be not long before he finishes his job.

13. It happens (seems, looks, appears ) that...

　　该句型中it是形式主语，that 引导的是主语从句，主句中的happen , seem等词是不及物动词． 　　

It happened ( so happened ) that he met his teacher in the street. 碰巧．． 　
It seems that he will be back in a few days. 看来．．．

14. It takes sb. ... to do sth.

　　该句型中的不定式是真正的主语，it是形式主语，句型中的直接宾语是时间。常译为＂做．．．要花费某人．．．＂。 　　

It took thousands of people many years to build the Great Wall.

15. It is no good (use ) doing sth.

　　该句型中的真正主语是动名词短语，主句中的表语可以是no good , ( not any good ) , no use , ( not any use )。 　　

It is no good learning English without speaking English.

16. It doesn’t matter whether ( if ) ...

　　该句型中whether(if) 引导的从句是真正主语，该句型常译为　＂不论（是否）．．．没关系．．．。 　　　
It doesn’t matter if they are old

17. It is kind ( of sb. ) to do sth.

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 do sth. 　

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

18. It is necessary ( for sb. ) to do sth.

　　该句型与上一个同属一个句型。如果不定式的逻辑主语是由for引起，主句中的形容词通常是表示重要性，紧迫性，频繁程度，难易，安全等情况的形容词。常见的形容词有：① important, necessary, natural ② easy , safe , common , normal , hard , difficult , dangerous , unusual, rare , impossible , pleasant等。 　　
在①中的形容词作表语可以用从句改写， 如： 　　
It is important for her to come to the party.
= It is important that she (should ) come to the party

19. It looks ( seems ) as if ...

　　该句型中it无意义。 as if 引导一个状语从句。常译为，＂看起来好象．．．＂如果与事实不相符合，则用虚拟语气．

It looks as if he is ill.（真的病了）　
It looks as if he were ill. （没有生病）
It seemed as if he were dying.

20. We think it important to learn a foreign language.

　　该句型中的it 作形式宾语。为了记忆方便我们可称该句型为"6123结构"。
　　6指主句中常用的动词：think, believe, make, find, consider, feel；
　　1指的是形式宾语it； 　
　　2指的是宾补的两种形式：形容词或名词；
　　3指的是真正宾语的三种形式：不定式短语，动名词短语或that引导的宾语从句。 　

We think it our duty to clean our classroom every day. 　
He felt it important learning English well. 　
They found it difficult that they would finish their work in two days.

1．It + 被动语态 + that…

1)It is widely recognized that extensive deforestation contributed to heavy summer flooding. （众所周知）

2)It is reported that 800000 applicants sat for the National Master’s Entrance Test in 2003. （据报道）

3)It is estimated that two thirds of the cities of our country will be in acute shortage of fresh water by 2010. （据估计）

4)It is generally accepted that to practice euthanasia on a patient who is still alive is inhuman. （人们普遍认为）

5)It must be admitted that the price war will disturb the normal order of the market. (必须承认)

6)It cannot be denied that the overgrowth of tourism may destroy the ecological balance of some scenic resorts. （不可否认）

7)It is known to all that physical exercises can improve and enrich our physical and mental well-being. （众所周知）

8)It goes without saying that our actual knowledge of natural laws is still imperfect and limited. （毫无疑问）

2．It is + 形容词 + to do sth / that…

1)It is obvious /evident /clear /apparent that the situation is caused directly by excessive commercial fishing. （很显然）

2)It is understandable (inevitable) that people’s attitudes are divergent on this controversial issue. （可以理解/不可避免的是）

3)It is unimaginable (incredible/unbelievable) that such a boy of 17 should have had three novels published. （难以置信的是）

4)It is imperative that something urgent be done to combat the widespread use of illegal drugs among teenagers. （…是很有必要的）

5)It is upsetting to find people who behave differently from us. We may, at first, assume that something is wrong with them. （…是令人恼火的）

6)It is impossible to concentrate if you are tense or nervous.（…是不可能的）

7)It is highly necessary for our government to stop the corruption of government officials.（某人很有必要做某事）

英语中it 一词结构看似简单，但其词义广泛，使用范围很广，常令一些初学者感到头痛。It用法及其句型和固定搭配，是英语语法的重点、难点，又是近几年考试的热点,在高考中也是重现率较高的语言点，其考查方式多通过“单项填空”进行，偶尔也出现在“短文改错”和“完形填空”中。因此在复习中应给予足够的重视。下面笔者就it的用法简单归纳如下。
一、 代替上文中提到过的人或事物。指代人时，一般用于小孩或身份不十分明朗的人。
1) －Who is the baby? －It‘s my teacher’s son．
2) －Who is that gentleman? －It's my friend Tom．He(不可用It) wants to see you．
不定代词one 指代前文提到的同类事物之一，而 it 特指上文中提到的同一事物。试对比：
This pair of shoes is small. May I have another one？（泛指的另一双）
这又鞋子太小了，再拿一双给我看看好吗
My pen is missing.Ican’td find it.
我的钢笔丢了找不到了(it指my pen)
二. it 作为无人称动词的主语，表示天气 ，时间，距离，环境情况等等。这时的it 不指某个具体的东西。没有明确的含义。译成汉语可不必译出来。如
1).It‘s half an hour’s walk from here to our school．
从这儿到我们学校是步行一个小时的路程
2) It‘s nice and warm here．
这里非常暖和
3) But it's two o'clock now, and it's time for us to go to school．
两点了该是上学的时间了
4) It’s quite close in the room . Let’s open the window for a while。
房间里太闷，把窗子打开一会儿吧。
三.“It” 可以代替指示代记词This ,that .
例：---Whose dictionary is that ?---It is mine
四,用作形式主语或形式宾语。
1. 当作主语的不定式、－ing短语或从句太长时，往往用it作形式主语，而将真正的主语移至句末，
以避免句子头重脚轻。it作形式主语的常见句型：
★it替代动词不定式作主语的常见句型为:
1) It is necessary /important /possible/easy…..for sb to do….
如:It is necessany to learn a foreign lanuage.学一门外语是有必要的。
It is kind /foolish/polite/brave/careless…of sb to do.常用形容词有:clever/wise/bright/silly/foolish/stupid/kind/cruel/right/wrong等如:
It is kind of you to help me=You are kind to help me.:谢谢你帮助我.
3)It is up to sb to do sth.该由某人做某事如:It is up to you to decide.由你来决定.
4)It is (not)like sb to do sth.做某事是(不)是某人的行为.如:It was not like you to have said such rude words.
说出这样粗鲁的话不像你的行为.
5)It is one’s turn to do sth.轮到某人做某事.如;It is your turn to speak 轮到你发言了.
6) It takes time to do sth .如:It took me an hour to finish reading the novel.读完这本小说花了我一个小时
★It替代动名词作主语的常见句型：
It’s no good/use doing… 如:It’s no use / good crying over spilt milk．覆水难收
It’s (well)worth (one’s )while doing/to dosth.
It’s worth（your）while to learn english。学英语是值得的.
★It替代主语从句常见句型:
1） It is a pity (a shame ,a fact ,a wonder ,a good thing ,good news etc)that……例如：
It is a shame that he didn’t pass the exam.
很遗憾他没有通过考试。
2） It is strange(natural surprising obvious true good wonderful possible,impossible,likely,unlikely,quite clear.certain ,etc) that… 。例如：
It was quite clear that they had no disire for peace.
很清楚他们没有和平的诚意。
3） It seems (happened ,turned out, occurred to sb etc.)that…例如：
It seemed that things were not as they expected.
看起来情况并不像他们所想象的那样。
4） It is said (reported ,decided ,expected ,arranged ,rumoured ,etc)that …例如：
It is said that the tickets have been sold out .
据说票已售完。
5) It is time that 从句（谓语用过去时）
It is time that he went to school.他本该去上学了.
6)It seems/appears/sounds/looksas if…….似乎/听起来/看起来….
It seems as if it is going to rain.仿佛要下雨了.
2当复合宾语中的宾语是不定式、－ing短语或从句，往往用it作形式宾语，而将真正的宾语移至句末，以使句子重心后移。
Do you think it a good habit to read in bed?
你认为在床上看书的习惯吗？
We find it difficult to learn English well in such a short time．
我们认为很难在这如此短的时间内学好英语
I will leave it to you to buy the ticket.
我要把买票的事委托给你
We think it no use crying over spilt milk．
我认为木已成舟哭也没用。
You may depend on it that they will support you.
你相信好了，他们会支持你的。
They will answer for it that the computer is reliable.
他们愿意保证这台电脑是可靠的。
We made it clear when and where we were going to have the meeting．
我们宣布了何时何地要举行会议。
I tookit for granted that you would stay with us .
我信以为真你要和我们呆在一起.
五.It用于强调结构：it没有具体意义，可强调谓语动词外的成分。其基本句型为：
It+be+被强调部分+that(who)+其它……。
★强调主语：
主语是人，一般用who （也可用that 其他情况用that.。强调主语用主格；who或that后面的句子中谓语动词与被强调的主语在数和人称上应保持一致。例如：
It is I who (that) am to blame
应付责任的是我。
It was you who didn’t keep your promise。
是你不遵守诺言
It was long overwork that made them get tired.
长期超负荷的劳动使他们疲被倦不堪。
★强调宾语：当宾语是指人的名词或代词时、强调句中的连接词用whom或that，其他情况用that。如：
It is you that we have been wanting to visit.
我们一直想去访问的是你。
★强调状语：被强调的状语可以是时间状语或地点状语，原因状语。强调句中的连接词只用that例如：
It was at that time that I thought of giring him a call.
直到那时我才想起要给他一个电话。
It was in the zoo that they saw the elephants.
他们是在动物园见的大象。
在运用it引导的强调句时，要注意以下几点：
1） 强调句的谓语is或was永远用单数，例如：
It was yesterday that I met your father in the street．
2）不管被强调部分是哪种状语，只能用that连接，不得使用where、when等连词。例如：
It was in the street that I met your father yesterday．
3）被强调部分为人时，可用who(主格)和whom(宾格)代替that，用that也行。例如：
It was your father that/whom I met in the street yesterday．
It was I that/who met your father in the street yesterday
4）强调句中 也要注意主谓一致、人称一致和否定转移的问题。例如：
It is they who are our friends．
5）not …untill…句型的强调形式为It is/was not untill that 例如:
It was not until ten o'clock that we got home last night．
6)as since because 均可引导原因状语从句,但是强调句型中只可以强调because从句例如:
It was because he was ill that he didn’t come here.
7)注意不要混淆强调句和其他从句。It is was…that…为强调句标志，去掉后仍可组成一个完整的句子，只是没被强,调,而其他从句一般不具备这一特征。
比较：
1) It was ten o'clock when we got home last night．我们昨晚到家时已十点了。
2) It was at ten o'clock that we got home last night．我们昨晚是在十点到家的。
3) It was not until ten o'clock that we got home last night．
8)强调句型的一般疑问句形式为: “Is/was＋it+被强调部分＋that/who/whom+其它?
其特殊疑问句形式为:Wh-疑问词/How+is/was+it+that” +其它?
what is it that you want to say ？
who was it that came here this morning！
六 .It is /was /will be long /not long /many years/howrs/a few
minutes before…表示 …去….就 /才“或”不多久就…
例： It was not long before the whole country rose up and drove the Austrian soldiers from their homeland.
It is …since 从句意思是；“自从。。。。以来已经多久了”。如果since从句中的谓语动词是短暂性动词，那么就表示该动作的开始，如果从句中的谓语动词是延续性动词或表示求态的动词，则指动作或求态的结束。
就学生而言：It is nearly 12 years since I became a stndent.
就老师而言：It is nearly 12 years since I was a stndent.
It’s the first/second/third time that+主语+ have/has+done/been…
主语第几次…(it 也可换成this that today等)如:
It’s the first time that I have come here.我第一次到这儿.
七、it 用于某些句语中，it 常用作某些动词的含糊宾语。例如：
That’s it.对了.
I can’t help it.=It can’t be helped.我无能为力.
It’s the same with sb.某人的情况也是一样.
Get with it ! 振作精神！
Keep at it ! 坚持下去！
Go it while you aire young.
趁你还年轻就努力干吧。
make it 规定时间，做到,成功。
Foot it 步行去
As it is/was 事实上。
Fight it ont 决一雌雄
keep at it 别松劲
Catch it 冒险，碰运气
Leg it 逃走
Brave it 敢干，抵抗
He thinks he is it .他自以为了不起。
Why ,among scientists,he is it.嗨，在科学家中他最出色。
巩固练习
1Was it during the Second World War ____ he died？(NMET88)
A．that B．While C．in which D．Then
2．Is ____ possible to fly to the moon in a spaceship？(NMET88)
A．now B．that C．it D．Man
3.I don't think ___ possible to master a foreign language without much momory work．(NMET90)
A．This B．that C．its D．It .
4. Does ___matter if he can’t finish the job on time?(NMET91)
A. This B.That C.He D.It
5.It was not ___she took off her dark glasses___Irealiced she was a famous film star. (NMET91)
A.When ,that B.Until,that C.Until.when D.When,then
6.It worried her a bit ___her hair was turning grey. ([NMET92]
A. Whit B.That C.If D.For
7.---What was the party line? ---Wonderful. It’s years___Ienjoyed myself to much.( NMET 93)
A. After B.Before C.when D.Since
8.Tom,s mother kept telling him that he should work harder,but___didn,t help. ,( NMET 93)
A. He B. Which C. She D. It
9.__is a fact that English is being accepted as an international langnage. (NMET 94)
A. There B.This C. That D. It
10..It was about 600 years ago ___ the first clock with face and an hour hand w was made (NMET97)
A．That B．Until C．before　D．when
11.______computers play such an important part in our daily life?
A.Why is it that B.Why it is that C.Why was it that D.Why is it
12. It was only when I reread his poems recently ___ I began to appreciate their beauty．(NMET98)
A．until B．that C．then D．so
13.,I hate____when people talk with their mouths full．,(NMET98)
A it B．that C．these D．them
14．Onford,as we know___,is one the best unirersities in the world.
A. that B.it c.this D.不填.
15.It was the third time I____to that city.
A.have been B had been C.came D. Was .
16.When was it____you arrived in New York?
A.that B.at which C.before D. Since.
17.It was____I met Mr.Green in Shanghai.
A. ten years since B.five years C.two months when D. many years ago that
18.Jack is ill,