1. It 的用法 It 最基本的用法是人称代词，主要代表刚提到的东西以 避免重复。 Look at that car. It’s going much too fast. Where is the car key? ---- I put it in your drawer. 也可以代表抽象的东西。 It’s all my fault. 也可以指动物或未知性别的婴儿。 What a beautiful baby--- is it a boy? How about the baby? ---- I’ll take care of it. 还可代表一个彼此都知其何所指的东西。 Where does it hurt? If he doesn’t come, I can’t help it. You have saved my life. I shall never forget it.

2. 非人称代词 it It 用于代替指示代词， It 可以表示 “ 是谁（在某处或做某事） ” “Who’s that?” “It’s me.” It’s your mother on the phone. “Why, it’s you!” she cried. It 还可以用来泛指某件事。 Isn’t it awful! It doesn’t matter. it 有时并不指具体东西，而指天气、时间、环境、距离 等，称为非人称代词 it. It’s raining. It’s Tuesday today. It’s quiet here. It’s two miles to the beach.

3. 形式主语 it 有下面几种类型： Be+ 形容词 + 不定式 eg: It’s better to be early. Be+ 名词 + 不定式 eg: It was his duty to take care of the orphans. Be+ 介词短语 + 不定式 eg: It’s beyond me to say why. It + 及物动词 + 宾语 + 不定式 eg: It makes me sick to think about it. Be+ 名词 + 动名词 eg: It’s no good/use standing here in the cold. Be + 形容词 + 动名词 eg: It’s interesting working with her. 其他结构 + 动名词 eg: It doesn’t matter waiting a few more days.

4. 用于由 that 引导的主语从句，有下面几种类型： it +be+ 形容词 +that 从句： eg: It is important/necessary that they should have different views. it +be+ 名词 +that 从句 : eg: It’s a shame /a pity /no wonder that you’re sick. it + 动词（ + 宾语） +that 从句 eg: It happened that she wasn’t in that day. eg: It never occurred to me that perhaps she was lying. eg: It doesn’t matter/ make any difference that he disagrees. It+ 动词的被动语态 (said/believed/thought/expected/reported/ Known +that 从句 eg: It’s said that there has been an earthquake in India.

5. 形式宾语 it: it 可以代表不定式或动名词： eg: She found it difficult to convince him. eg: He felt it his duty to take care of them. eg: I think it useless quarreling with her. It 代表 that 引导或代表连接代（副）词引导的从句： eg: I took it for granted (that) you would be coming. eg: I have made it clear that noby is allowed to smoke here. eg: He hasn’t made it clear when he is coming back. eg: I hate it when people talk with their mouth full.

6. 用 it 起始的句型归纳： 1 ） it +be+ 形容词 + 从句： eg: It is not clear to me why he behaved like that. 2 ） it +be+ 名词 + 从句 : eg: It’s a puzzle how life began. 3 ） it + 动词（ + 宾语） + 从句 eg: It doesn’t matter much where we live. eg2: It makes no difference whether we go by train or by boat. 4 ） it + 动词的被动语态 + 从句 eg: It is not decided who will edit it.

7. 5 ） It +be + 具体时间 + when… eg: It was Christmas Eve when I got the news of his being killed in a car crash. 6 ） It + be + 一段时间 +before + 从句 eg: It won’t be long before he comes back. 7 ） It +be+ 一段时间 + since… Eg: It is/has been three week since I last heard from him. 8 ） It is time to do/ that…( 谓语用过去时态） Eg: It is time for us to give the house a thorough cleaning. It is time that we gave the house a thorough cleaning.

8. 9 ） It + be + the first/second time that…( 谓语动词用完成时态） Eg: It is the first time in history that two Nobel Prizes have been awarded to the same person. 10 ） It takes sb. some time to do… Eg: It took Mary 20 minutes to choose a suitable dress for the party.

9. It 用于强调句 结构： It+ 动词 be+ 强调部分 +who(whom)/that+ 其他部分 it 可以用来对句子的某一成分加以强调。 Eg: Nancy saw your sister in Tokyo last week. It was Nancy who saw your sister in Tokyo last week. It was your sister whom Nancy saw in Tokyo last week. It was in Tokyo that Nancy saw your sister last week. It was last week that Nancy saw your sister in Tokyo.

10. 有些否定句也可以改成这种强调结构： I didn’t hear from her until last summer. It wasn’t until last summer that I heard from her. I didn’t do all this for myself. It wasn’t for myself that I did all this. 问句也可变成这种结构： Who called him “comrade”? Who was it that called him “comrade”? How did you forget to lock the door? How was it that you forgot to lock the door?

11. Ex: 把下列句子改为强调句： 1.Tom broke the window last night. 2. They want money. 3. Peter saw his friend in the park yesterday. 4. I didn’t have an opportunity of seeing her again for several years. 5. Why does everyone think I’m narrow-minded? 6. I didn’t receive my letter until yesterday? 7. Did Dick call the meeting last week? 8. Did it happen in 1980?

12. There 起始的句型归纳： 1 ） There live/stand/lie/exist… Eg: There stands a big tree at the entrance to the temple. There lay a ditch two metres wide ahead. 2) There being… （独立主格结构） Eg: There being nothing left in the fridge, we had to do some shopping first. 3) There is no doubt that/ There is some doubt wheather…. Eg: There is no doubt that we Chinese will overcome the difficulties.

13. 4) There is no need to do… Eg: There is no need to wait for the bus since we can take you in our car. 若名词是 harm, sense, point 时 There is no + 名词 + in doing… Eg: There is no point in arguing with him. He won’t listen to anyone. 5) There appear/seem/is likely/is certain to be… Eg: There seems to be something wrong with the electric fan. There is likely to be more people at the speech co0ntest than expected.