it作形式主语的几大基本句型

it作形式主语的几大基本句型

形式主语，顾名思义，即形式上是主语，但实际上不是真正的主语，真正的主语是后面的动词不定式、动名词或主语从句等。如果让后面的动词不定式、动名词或主语从句用作主语，那么在句式上容易造成“头重脚轻”，句式不平衡，故往往用it作形式主语，而把真正的主语放在后面。it在这里没有任何意义。初中阶段，it作为形式主语常常用在以下几个句型。（为避免混淆，本文暂时省略了另两大句型，日后再论）

◇It’s +形容词/名词+that +从句

It is necessary that you train yourself before the walk.

It is important that you have your own support team.

It was a pity that he lost the game.

It’s a pity that you missed the exciting football match.

◇It’s +形容词+(for sb) +to do sth

It is difficult to walk through eight country parks.

It is useful to have support teams.

It is important for him to finish it in ten hours.

It is necessary for people to learn team spirit.

特别提醒：

☆该句型的否定结构为It’s +形容词+(for sb) +not +to do sth

It is very important not to give them too much food. (7B 100)

It is very polite not to speak loudly in public.

☆该句型有时可以与It is + adj. + that从句的句型互换使用，意思不变。如：

It is necessary for you to train yourself before the walk.

= It is necessary that you will train yourself before the walk.

◇It’s +名词+to do sth

It’s everyone’s duty to obey the law.

It is not a good habit to stay up too late.

As a student, it is bad manners to come late to class.

It is my turn to clean the blackboard.

◇It takes sb +some time to do sth

It took us two hours to set up the stage.

◇It seems that +从句

It seemed that he didn’t tell the truth.

◇It’s +过去分词+从句

惯用句型有：It is said that(据说), It is reported that(据报道), It is believed that(大家相信), It is hoped

that(大家希望), It is well known that(众所周知), It is thought that(大家认为), It is suggested that(据建议)等。

It is reported that 16 people were killed in the earthquake.

翻译句子：

1. 一些人瞧不起盲人是错误的。

2. 我们有必要帮助残疾人。

3. 真遗憾，他犯了这样一个错误。

4. 据说他已去美国深造了。

5. 看来他似乎有病。

6. 别给孩子太多的钱很重要。

7. 我的职责就是扫地。

8. 他每天花半个小时乘地铁上班。

江苏13城市中考试题汇编：

单项选择：

( ) 1. We think it is difficult _______ them ________ the charity walk without team spirit. (2010南通)

A. for; to finish

B. of; to finish

C. for; finishing

D. of; finishing

用所给单词的适当形式填空：

1. It is important for us _______(take) action to prevent A-Flu-H1N1 spreading. (09泰州)

翻译句子：

1. 对你来说，如果想获得成功，不要轻易放弃是很重要的。(08扬州)

_____________________ if you want to achieve success.

2. 我们中的一些人瞧不起残疾人是错误的。（08宿迁）

It’s wrong that some of us ___________________ the disabled.

3. 我认为嘲笑别人是不礼貌的。（09淮安）

I think it’s ____________________________________.

4. 对我们来说，做好每一件事是很有必要的。（09盐城）

It’s very necessary _____________________________.

5. 对于年轻人来说学会团队精神很重要。（2010扬州）

________________________________________________.

6. 原谅那个年轻人又一次迟到是不明智的。（2010常州）

It’s not wise _____________________________.

Keys：

1. It is wrong that some people look down on blind people.

=It is wrong for some people to look down on blind people.

2. It is necessary that we help the elderly.

=It is necessary for us to help the elderly.

3. It is a pity that she has made such a mistake.

4. It is said that he has gone to the USA for further study.

5. It seems that he is sick.

= He seems to be sick.