英语中it用法.doc

it用法完全归纳一、it 作人称代词的用法1. 指事物作为人称代词，it 可以除人以外的一切事物或动物。如：I dropped my watch and it broke. 我把手表掉在地上摔坏了。Its hard work, but I enjoy it. 工作很辛苦，可是我乐意干。“Where is the dog?” “Its in the bedroom. ” “狗在哪?”“在卧室里”。2. 指人it 指人主要用于指不性别不明的婴儿或用于确认某人的身份。如：Is it a boy or a girl? 是男孩还是女孩?There is a knock on the door. It must be the postman. 有人在敲门，一定是邮递员。【说明】在答语中，常用来指本人，如说 Its me。3. 代替某些代词代词 it 还可用于代替指示代词this, that 以及复合不定代词 something, anything, nothing等。如：“Whats this?” “Its a new machine. ” “这是什么?”“是一种新机器”。Nothing is wrong, is it? 没出什么问题，是吗?二、it 作非人称代词的用法1. 基本用法it 作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。如：Its too late to go there now. 现在去那儿已经太迟了。It rained all day yesterday. 昨天下了一天的雨。It can get very hot here. 这里有时会很热。2. 用于某些句型Its time for sth. 该做某事了。Its time to do sth. 该做某事的时候了。Its time for sb to do sth. 某人该干某事了。Its (about / high) time + that-从句. 某人该做某事了。(从句谓语用过去式，有时也用“should+动词原形”)Its first (second) time + that-从句. 某人第几次干某事。(从句谓语用现在完成时)Its + 时间段 + since-从句. 自从有一段时间了。Its + 时间段 + before-从句. 过多长的时间才三、it用作形式主语1. 基本用法当不定式、动名词、从句等复杂成分用作句子主语时，为保持句子平衡，通常把真正的主语放在句末，而在句首使用形式主语it。如：Its very important to remember this. 记住这一点很重要。Its hard work climbing mountains. 爬山是费劲的事。Its unknown when he will come. 他什么时候来还不知道。2. 用作形式主语的的重要句型(1) It + be + adj. for (of) sb to do sth 某人做某事It is hard for him to make up his mind. 他很难下定决心。It was foolish of her to say such a thing. 她说那样的话，真是太蠢了。【说明】介词 of 与 for 的区别是：of 用于指某人的性格、属性、特征等，介词for表示对象，意为“对来说”。(2) It takes sb + 时间段 + to do sth. 某人做某事花了时间It takes years to master a new language. 要花多年的时间才能掌握一门新的语言。【说明】此句型可以有以下多变种变体：It took me an hour to write the letter. =The letter took me an hour (to write). =I took an hour to write the letter. 我写这封信花了一个小时。(3) It is up to sb to do sth. 该由某人做某事Its up to you to to make the choice. 得由你来作选择。(4) it look (seem, appear, happen, occur) that as if 似乎It seemed as though he didnt recognize me. 他似乎没认出我来。It happened that I was out when he called. 他打电话时我碰巧不在家。(5) If it were not for / If it hadnt been for 若不是因为If it were not for their help, we couldnt have got over the difficulties. 要不是他们帮助，这些困难我们不克服不了的。四、it用作形式宾语1. 基本用法当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语，而将真正的宾语移至句末。其基本结构为“动词+it+宾语补足语+不定式(动名词或从句)”。如：I find it difficult to do the job well. 我发现做好这件事不容易。I think it best that you should stay here. 我认为你最好住这儿。We think it no use complaining. 我们认为抱怨是没有用的。2. 用作形式宾语的几个特殊结构(1) 动词+ it + that-从句。如：I like it that you came. 你来了，我很高兴。I take it (that) he will come on time. 我认为他会准时来的。You can put it that it was arranged before. 你可以说这是以前安排的。Rumor has it that the defense minister will soon resign. 据传闻，国防部长不久就要辞职。【说明】能用于此结构的动词不多，常见的有 have, take, put, like 等。(2) 动词 + it + when (if)-从句。如：I dislike it when you whistle. 我不爱听你吹口哨。We really appreciate it when she offered to help. 她来帮忙了，我们十分感激。Id prefer it if I didnt have to do so much work. 要是我不必做那么多工作，好就太好了。【说明】能用于此结构的动词不多，常见的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。(3) 动词 + prep + it + that-从句。如：See to it that youre not late again. 注意千万不要再迟到。Look to it that this doesnt happen again. 注意不要再发生这种事。You may rely on it that hell come to meet you. 你放心，他会来接你的。I cant answer for it that he will come. 我不能保证他会来。【说明】能用于此结构的动词不多，常见的有see to, look to, insist on, stick to, depend on, answer for 等。(4) 动词 + it + 介词短语+ that-从句。如：I owe it to you that I am still alive. 多亏有你我才仍然活着。I took it for granted that he would help us. 我认为他会帮助我们的。【说明】能用于此结构的动词不多，常见的有take it for granted, bring it to sbs attention, owe it to sb 等。代词it基本用法小结人称代词it可以用来代替一个名词、一个短语、一个从句或一个句子，以避免它们在句中的重复。这时它可以指提到过的，也可以指未提到过的，在句中作主语或宾语。(1) 替代刚提到过的同一事物This is our new car. I bought it yesterday. 这是我们的新车。我昨天买的。(2) 指动物或不考虑性别的婴儿Where is the cat? Its under the bed. 猫在哪？它在床下面。The baby cried when it was hungry. 这婴儿饿时就哭。(3) 在情景中确认某人或事物Who is it? Its me. 是谁？(问敲门人) 是我呀。Whos it over there? Its the milkman. 那边那人是谁？那是送牛奶的Whats this? Its a map. 这是什么？这是张地图。(4) 指代前句或后句所述的情况He smokes in bed and I dont like it. 他在床上抽烟，我不喜欢他这样。When the factory closes, it will mean 500 workers will be out of work. 工厂一旦关闭, 那就意味着要有500工人失业。It would be ideal if you could join us. 如果你能和我们合作，则太好了。(5) 指时间、距离、天气或环境等What time is it? Its seven oclock. 几点了？7点。Its time for supper. =Its time to have supper. 是该吃晚饭的时候了。Its about 50 kilometers from here to my home. 从这儿到我家约有五十公里。It is snowing. 正在下雪It was very quiet in the garden. 公园里很寂静。(6) 用于笼统地谈论某种情况I cannot help it. 我也没办法。(7) 指最好的或最渴望得到事物He thinks hes it. 他一直以为自己是最佳人选。That steak was really it! 那牛排真是不错！Weve been looking for a house for months and I think this is it. 我们找房子已经找了好几个月了, 我看这所就是我们要找的。含it的9个常用特殊句型1. It doesnt matterIt doesnt matter what he says. 他说什么都没关系。2. It appears/ seems/ happens/says thatIt seems that he is always correct. 他好像总是对的。It happened that I had no money with me. 碰巧我当时没有带钱。3. It is said/ reported/ believed/ understood thatIt is said that he has joined the Party. 据说他已经入党了。4. It is a waste of time /money doing sth. Its a waste of time your talking to him. 你和他谈是浪费时间。5. (It is) no wonder( that) Its no wonder he is not hungry; he has been eating sweets all day. 难怪他不饿，他整天在吃糖果。6. It makes no/mush differenceIts doesnt make much difference my being there. 我在不在那儿没有什么影响。7. it takes sb. some time to do sth. It took me nearly an hour to work out the problem. 花了我差不多一个钟才做出那道题. 8. Its ones turn to do sth. Its my turn to clean the classroom. 是轮到我打扫教室的了。9. If it were not forIf it were not for your help, I would still be homeless. 若不是你帮忙，我现在还是无家可归。哪些从句作主语时可用it作形式主语原则上说，it用作形式主语可以代替下列从句：1. that从句It is quite clear that he has read the book. 很显然，他读过这本书。(HM)2. what从句It doesnt matter what he says. 他说什么没关系。(HM)It was clear enough what he meant. 他的意思是很明显的。3. who从句It hasnt been decided who will be sent to work there. 还没决定将派谁到那里工作。4. how从句It struck her how gentle he was being. 她深深感到他多么温存。5. when从句It hasnt been made clear when the conference is to take place. 会议什么时候召开还没有宣布。6. where从句Its not known where she went. 她到哪里去了没人知道。It did not matter much where he lived. 他在哪里住都没有关系。7. why从句It was clear why he had asked for a conference. 他为什么要求召开会议原因很清楚。8. whether从句It makes little difference whetherwe go or stay. 我们去还是留没有多大差别。Its not yet settled whether I am going to America. 我去不去美国还没定。it用作形式主语代替动名词主要用于哪些句式it用作形式主语代替动名词的用法主要见于以下句式： 1. It is no use (no good, fun, great fun, a new experience, a great honour, etc) doing sth。如：It is no good talking. 空谈是没有用的。Its fun working for him. 为他工作很有意思。Its great fun sailing a boat. 扬帆驾舟十分有