it用法完全归纳.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)It is (was) 被强调部分+ that (who) + 句子其他部分.此结构强调的成分仅限于主语,宾语和状语.It is from the sun that we get light and heat.It was not until I had read your letter that I understood the true state of affairs.典型例题 1） It was last night _ I saw the comet(彗星).A.the time B.when C.that D.which 答案C.强调句的结构是：It +be +强调部分 + that (who) + 主谓句.强调句的连词只有两个,that和who.当强调的部分是人,且为句子的主语时,才用 "who",其余用that.原句：My father did the experiment in the lab yesterday evening.强调主语：It was my father who did the experiment in the lab yesterday evening.强调宾语：It was the experiment that my father did in the lab yesterday evening.强调时间：It was yesterday evening that my father did the experiment in the lab.(注意不用when) 强调地点：It was in the lab that my father did the experiment yesterday evening.4、 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。 【说明】能用于此结构的动词不多，常见的有takeitforgranted,bringittosbsattention,oweittosb等。It 的用法练习 一单项选择。 1.Was it during the Second World War _he died? A.that B.while C.in which D.then 2.Is _ necessary to take off our shoes when we enter the lab? A. everyone B.this C.her D.it 3. Is _ possible to fly to the moon in a spaceship? A.now B.that C.it D.man 4. I dont think _ possible to master a foreign language without much memory work. A.this B.that C.its D.it 5.She heard of a terrible noise, _ brought her heart into her mouth. A.it B.which C.this D.that 6.Alice received an invitation from her boss, _ came as a surprise. A.it B.that C.which D.he 7. Does _ matter if he cant finish the job on time? A.this B.that C.he D.it （补充定语从句中which还有一种特殊用法，它可以引导从句修饰前面的整个主句，代替主句所表示的整体概念或部分概念。在这种从句中，which可以作主语，也可以作宾语或表语，多数情况下意思是与and this 相似，例如： He succeeded in the competition, which made his parents very happy. ） 8.Toms mother kept telling him that he should work harder, but _ didnt help. A.he B.which C.she D.it 9.The weather turned out to be very good, _ was more than we could expect. A.what B.which C.that D.it 10._is a fact that English is being accepted as an international language. A.There B.This C.That D.It 12.It was about 600 years ago_the first clock with a face and an hour hand was made. A.that B.until C.before D.when 13.I hate _ when people talk with their mouths full. A.it B.that C.these D.them 14.It was only when I reread his poems recently_ I began to appreciate their beauty. A.until B.that C.then D.so 15.It is the ability to do the job _ matters not where you come from or what you are. A.one B.that C.what D.it 16. It _ you that _ to blame. A.is;is B.is; are C.are;are D.are;is 17.Was_that I saw last night at the concert? A. it you B.not you C.you D.that you 18._ electricity plays such an important part in our life? A.Why is it that B.Why is it C.Why it is that D.Why is that 19.It was _ he said _ disappointed me. A.what;what B.that;that C.what;that D.that;what 20.It was in the lab _ was taken charge of by Professor Harris _ they did the experiment. A.which; that B.that; what C.whom; that D.which; where 1-5ADCDB 6-10CDDBD 11-15DAABB 16-20BAACA