it-用法总结.doc

It的用法总结在英语中,it有许多不同的用法,它既可以用作代词(如人称代词、非人称代词)，也可以用作引导词（作形式主语或形式宾语），还可以用来构成强调句型。1. it用作代词(1) 用作人称代词 在句子中作主语或宾语；指前面已经提到过的事物、动物或人，且it指特定的事物；如果指前文中提到的事物中的任何一个，用one。one可以与any, each, every, not等连用，但one不可代替不可数名词。Wheres your car? Its in the garage. 你的汽车在哪儿呢？在车库里。(指代物品your car)Did you hit it? 你打中了吗？ (指代事件)The baby cried when it was hungry.这婴儿饿时就哭。（指代婴儿，尤指性别不详或无所谓时）Who is that?Its me. 是谁？我。(指一定情景中所确定的人或事物，此时相当于指示代词，代指this和that,有时也指人)Whats this? Its a box. 这是什么？一只箱子。(2) 作非人称代词 表示天气、日期、时间、温度、距离、价值、路程、度量、自然现象与环境等。也可模糊地指一般情形或上文的部分或整个意思。译成汉语时，it通常不一定译出来。Its a long time since they left. 他们走后很久了。Its two miles to the beach.离海滨有两英里远。Thats just itI cant work when youre making so much noise.原因就在这里你弄出这么大的声音，我工作不了。另外，需要注意两点：（1）“Its time”后面可以接不定式和介词短语表示“是做的时候了”。如：Its time for supper. Its time to have supper.(2) “Its time”后面还可以接一个从句，但是从句中的谓语动词一定要用过去式即虚拟语气，如： Its time we had lunch.是我们吃饭的时候了。 Its time we started.是我们该出发的时候了。2. it用作引导词(1) 作形式主语 由动词不定式、动词-ing短语或名词性从句担任主语的句子，常用it来作形式主语，而把真正的主语放在句子的后面。Its not easy for us to learn English well. 句型为: It +be+形容词+（for sb.）to do sth.Its foolish of you to say that to her. 句型为: It +be+形容词+（of sb.）+to do sth.Its no use/good/helpsleeping too much. (句型为: It +be+名词+doing) Its important that we be there on time.（句型为: It +be +形容词+that从句）Its high time that Tom went to school. (句型为: It +be +time +that从句，从句中的动词用过去时)It was the second time that he had telephoned me that day. 句型为: It +be+ the first(second, third)time +that从句（that从句中动词用完成时）It was arranged that they should leave the following winter. (句型为: It +be+过去分词+that从句)It appears that the two leaders are holding secret talks. (句型为: It +不及物动词+that从句) (2) 作形式宾语 当宾语是动词不定式、动词-ing短语或名词性从句时，而宾语后又有宾语补足语，则需用it作形式宾语，将真正的宾语放到宾语补足语的后面。用于这种结构的动词有：feel, find, think, make, consider, take等。Marx found it important to study the situation in Russia.马克思发现研究俄国的形势很重要。 I find it strange that she doesnt want to travel.她竟不想旅游,我觉得很奇怪。I ll make it clear to you that failure is the mother of success.我要告诉你们失败是成功之母。3. it用在强调句型中英语中，为了突出句子中的某一成分，达到强调或使人特别注意该成分的目的，人们常用“It is/was+强调对象+who/whom/that.”句式把整个句子分割成前后两个部分，使之各自有自己的谓语动词，中间由that或who/whom连起来成为一个新句子。除强调人时用who, whom外，其余情况都用连词that。被强调的对象仅限于句子的主语、宾语、宾语补足语和部分状语（包括状语从句），即除谓语和定语以外的句子成分。这部分状语主要包括地点状语、由before, when, after, not until等引起的时间状语从句、由because, because of引起的原因状语、由by引起的方式状语等。当被强调的对象是人时，可用who, whom或that，其余情况一律用that; 当被强调对象在从句中做主语时用who/that,当被强调对象在从句中做宾语时用whom/that。原句：My father did the experiment in the lab yesterday evening.昨天晚上我父亲在实验室做实验。It was my father did the experiment in the lab yesterday evening.昨天晚上是我父亲在实验室做实验。（强调主语）It was the experiment that my father did in the lab yesterday evening.昨天晚上我父亲在实验室里做的是实验。（强调宾语）It was yesterday evening that my father did the experiment in the lab.我父亲是昨天晚上在实验室做实验的。（强调时间状语）It was in the lab that my father did the experiment yesterday evening.我父亲昨天晚上是在实验室里做这个实验的。（强调地点状语）另外，再注意两点：（1）强调句如果还原成陈述句的话，句子成分是完整的，如果不完整，那必然是别的从句而不是强调句。It was the town where we lived for three years.此句是定语从句，因为还原以后的句子为:We lived the town for three years.缺少介词（in the town）, 而It was in the town that we lived for three years.这就是一个强调句了。（2）强调中心也可以是疑问词，这时要将疑问词置于句首，构成一个特殊疑问句。Why is it that you want to leave so soon? 你到底为何这么早就要走？It用法大总结(中) 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. It is strange that he should have said those 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 man-made satellite has been put into orbit6. It is suggested ( ordered, required . ) 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.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 常用过去时态表示虚拟 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 (This) is the first time I have been here. It ( This) was the first time I had been here一、人称代词1，it的最基本用法是作代词，主要指刚提到的事物，以避免重复: They watched the train until it disappeared in the distance.2.，也可以指动物或婴儿(未知性别的婴儿或孩子): Is this your dog？No, it isnt.They got a baby and it was a ten-pounder3.，也可指抽象事物或指抽象环境和情景:I hate it when people talk with a full mouth. 二、.非人称代词1.it有时并不指具体的东西而泛指天气、时间、日期、距离、价值、度量、温度、环境等： .指天气：It is a lovely day, isnt it? .指时间: It was nearly midnight when she came back.指日期:It is April First today.指距离:It is some 3000 kilometers from Beijing to Guangzhou.指价值:It is three dollars.指温度:Today it is 30 degrees centigrade. 三、其他用法1.在句子的主语不太明确时充当主语，表示谁在做某事： Who is it there? Its I (me/you/he.).I thought it was Mary, but it was not she.Her face lighted when she saw who it was. 2.泛泛的指某件事： (有时泛指一般情况)It doesnt matter. It is a shame, isnt it?How is it going?(情况怎样)It says in the newspaper that.3.it用在一些词组中，it 没有特别的意思The last trains gone. Come on, well foot it.(来，咱们步行吧。)四、作形式主语，替代主语从句，动词不定式，或动名词短语： 1.作形式主语替代主语从句It is clear ( obvious， true， possible， certain.) that 从句 常译为清楚的（显然的，真的，可能的,肯定的）It is very clear that hes round and tall like a tree. = That hes round and tall like a tree is very clear. It is important ( necessary， right， strange， natural.) that 从句 常译为是重要的(必要的,对的,奇怪的,自然的).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. It is said (reported/ learned/believed/thought/known/told/hoped.) that 从句 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. It is suggested ( advised/ ordered / demanded/ insisted/ commanded. ) that 从句.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. It is time ( about time ，high time ) that从句(虚拟语气:动词用过去时did) It is time that children went to bed. It is time you bought a new car. It is (high ) time you made up your mind.It is the first ( second . ) time that从句(从句用现在完成时 have done )It was the first ( second . ) time that从句(从句用过去完成时had done )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 hereIt is a pity ( a shame /an honour/a good thing/a fact,/a surprise/. ) that从句. 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！ It happens (seems， looks， appears ) that从句.常译为 “ 碰巧,似乎是,看起来” 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 2.作形式主语替代不定式 It is kind ( of sb. ) to do sth. 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褒义或贬义形容词。 常见的词有：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. 。如:It is kind of you to say so. = You are kind to say so. It is necessary ( for sb. ) to do sth. .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，安全等情况的中性形容词。 常见的形容词有：important， necessary， natural easy ， safe ， common ， normal ， hard ， difficult ， dangerous ， unusual， rare ， impossible ， pleasant 如:It is important for her to come to the party. = It is important that she (should ) come to the party. It takes sb. . to do sth. 常译为做要花费某人。 如:It took thousands of people many years to build the Great Wall.3.作形式主语替代动名词短语It is no good / no use / useless doing sth. 常译为 “有好处或没有用” It is no good learning English without speaking English. Its useless trying to argue with Shylock. 五、作形式宾语，代替不定式，动名词短语或宾语从句。We think it important to learn a foreign language.该句型中的it 作形式宾语，该结构中常用的动词有：think, believe, make ,find consider, fe