英语中it用法省公共课一等奖全国赛课获奖课件.pptx

it使用方法第1页it用作主语用作主语it指代事物、动物、婴儿或未知人What is this?-It is a book.Someone is at the door.-Who is it?Her new baby is tiny.It only weighs 2 kilos.第2页指代天气、时间、距离、季节、事物状态指代天气、时间、距离、季节、事物状态和自然环境等和自然环境等It is getting colder and colder.It is two years since I last saw you.It was very quiet in the cafe.How is it with Mr.Rose?It is only twenty minutes drive to our college.第3页it 作形式主语，代替不定式、动名词或从句，作形式主语，代替不定式、动名词或从句，使原来这些主语能够放在句子后面，防止句使原来这些主语能够放在句子后面，防止句子头重脚轻。子头重脚轻。1.it代替不定式作主语代替不定式作主语It cost me$25 to buy the dictionary.Is it necessary to complete the design before National Day?Its a good idea to have a little note book handby.第4页注意：注意：有时不定式前面有一个有时不定式前面有一个for引发短语，表示不定引发短语，表示不定式逻辑上主语，用式逻辑上主语，用it作形式主语时，组成下面句型作形式主语时，组成下面句型It is+adj.+for sb.+to do此句型中形容词为静态形容词，即描写人或物静态特此句型中形容词为静态形容词，即描写人或物静态特征形容词，用来表示客观情况。这么形容词有：征形容词，用来表示客观情况。这么形容词有：easy,difficult,important,hard,necessary,essencial,impossible,dangerous,common,unusual,big,small,tall,long,short,wide,old,young,beautiful等第5页It is very difficut for me to learn Spanish.It is getting harder every day for a poor man to get a living.注意：注意：有时不定式前面有一个有时不定式前面有一个of引发短语，引发短语，表示不定式逻辑上主语，用表示不定式逻辑上主语，用it作形式主语时，作形式主语时，组成下面句型：组成下面句型：It is+adj.+of sb.+to do此句型中形容词为动态形容词，即指那些有此句型中形容词为动态形容词，即指那些有动作含义词，或为描写人或物特征或品质形动作含义词，或为描写人或物特征或品质形容词，这么形容词有：容词，这么形容词有：第6页bold,brave,busy,careful,careless,clever,considerate,cruel,foolish,friendly,generous,good,honest,kind,lazy,nice,noisy,polite,rude,reasonable,selfish,shy,silly,stupid,thoughtful,wicked等It was generous of you to contribute so much.It was careless of her to lose her key of the safe.第7页2.it代替动名词作形式主语，而作主语动名代替动名词作形式主语，而作主语动名词常放在表语后，在此句型中表语有以下词常放在表语后，在此句型中表语有以下名词和形容词：名词和形容词：no good,no use,a waste of time,fun,hard work,pity,a wonder,dangerous,difficult,senseless,useless,foolish,nice,hard,interesting,worth,worthwhile,terrible,tiring,funny第8页Its no use studying for an exam at the last minute.It is difficult finding your way around here.3.it代替从句作主语，有以下四个常见句型代替从句作主语，有以下四个常见句型1)It+be+adj.+that从句从句这么这么adj通常有：通常有：possible/probable/likely 很可能很可能impossible/unlikely 不可能不可能obvious 显而易见显而易见certain 很必定很必定第9页plain 很显著 true 真clear 很清楚 fortunate 幸运是It was quite plain that she didnt want to come.How is it possible that a man can fall so low?注意：注意：当形容词为以下形容词时，从句可用虚当形容词为以下形容词时，从句可用虚拟语气拟语气,为（为（should+）动词原形）动词原形advisable 适当，合理地 better 很好preferable 优越，很好 essential 必要第10页important 主要 insistent 坚持natural 自然 necessary 必要desirable 理想 urgent 紧迫unfair 不公平It is unfair that so many people should lose their jobs.It is essential that you(should)win the voters hearts.It is important that this mission not fail.第11页2)it+be+n.+that从句从句common knowledge 常识 an honour 非常荣幸 a shame 可耻a wonder 是个奇迹 no wonder 不足为奇a fact 事实 good news 好消息a pity 遗憾 a question 问题It is a wonder that he is still ailve.It is still a question when we shall have our sports meet.第12页注意：在此句型中，假如表示诧异、遗憾等在此句型中，假如表示诧异、遗憾等感情，感情，that引导从句谓语动词惯用虚拟语气引导从句谓语动词惯用虚拟语气“(should)+动词原形动词原形”，但假如表示事实，但假如表示事实，谓语动词就不用虚拟谓语动词就不用虚拟It is a pity that you should have to leave.很遗憾你不得不离开It is a pity that you left.遗憾是你离开了第13页3)It+be+过去分词过去分词+that从句从句It is said that.听说。听说。It is reported that.据报道。据报道。It is believed that.据认为。据认为。It is announced that.据宣告。据宣告。It must be pointed out that.必须指出。必须指出。It has been proved that.已证实。已证实。It is estimated that.据预计。据预计。It must be admitted that.必须认可。必须认可。It can thus be coucluded that.能够由此得出结论。能够由此得出结论。第14页It was reported that they had brought down two enemy planes.(击落飞机)注意：注意：假如过去分词表示假如过去分词表示“提议、命令、愿望提议、命令、愿望”等含等含义词，从句用虚拟语气义词，从句用虚拟语气“(should)+动词原形动词原形”suggested 提议 ordered 命令requested 要求 desired 希望demanded 要求 required 要求recommended 提议 decided 决定insisted 果断要求 commanded 命令 第15页It is recommended that the project(should)not start until all the preparations have been made.It was suggested that he(should)join the club activities.4)It+不及物动词不及物动词+that从句，此句型中从句，此句型中that从句能够看做是句子主语，但不能放句首，从句能够看做是句子主语，但不能放句首，其句型为：其句型为：第16页It seems that.好像是。It happened that.恰巧。It follows that.由此可见。It matters that.要紧是。It occurred to me that.我突然想到。It struck me that.我突然想到。Didnt it occur to you that your husband might be late?It is said that they are a happy pair.第17页it用作宾语用作宾语it作宾语，指代前面提到一样东西、一个动物、一个婴儿或一件事情Did you see the snake?-Yes,I saw it.How about the baby?-Ill take care of it.Have you got my express mail?-Yes,Ive got it.If I have improved in any way,I owe it all to you.第18页it作形式宾语，惯用在以下动词后：作形式宾语，惯用在以下动词后：consider,think,find,count(把.认为),feel,judge有以下几个常见句型：有以下几个常见句型：1.主语主语+及物动词及物动词+it+形容词形容词(作宾补作宾补)+不定不定式式(真正宾语真正宾语)常见形容词有：常见形容词有：第19页possible 很可能 difficult 困难impossible 不可能 wise 明智unwise 不明智 necessary 必要interesting 有趣 better 更加好些wrong 错误They judged it better to put off the meeting.I felt it necessary to make everything clear.第20页2.主语主语+及物动词及物动词+it+名词名词(作宾补作宾补)+不定式不定式(真正真正宾语宾语)常见名词有常见名词有ones duty 某人职责 an honour 非常荣幸common knowledge 常识a question 问题 ones business 某人事a wonder 是个奇迹 no wonder 不足为奇good news 好消息 a shame 可耻a pity 遗憾第21页Ill make it my business to help her.I dont think it a question for him to finish everything in one week.3.主语主语+及物动词及物动词+it+名词名词/形容词形容词/过去分词过去分词(作宾补作宾补)+that从句从句(真正宾语真正宾语)常见名词有：第22页ones duty 某人职责 an honour 非常荣幸common knowledge 常识a question 问题 ones business 某人事a wonder 是个奇迹 no wonder 不足为奇good news 好消息 a shame 可耻a pity 遗憾第23页常见形容词有：possible 很可能 difficult 困难impossible 不可能 wise 明智unwise 不明智 necessary 必要interesting 有趣 better 更加好些wrong 错误第24页They kept it quiet that he was dead.We all think it a wonder that they finished the project in such a short time.We heard it said that the meeting would be postponed.4.主语主语+及物动词及物动词+it+名词名词/形容词形容词(作宾补作宾补)+动动名词名词(真正宾语真正宾语)在此句型中常见形容词及名词有：第25页no good,no use,a waster of time,fun,hard work,a pity,a wonder,dangerous,difficult,senseless,useless,foolish,nice,tiring,funny,hard,interesting,worth,worthwhile,terribleHe found it no use writing to him.I think it dangerous swimming in such a deep river.第26页5.it作宾语，用在一些特殊句型中See to it that you are not late again.注意别再迟到了You can put it that it was arranged before.你能够说这是以前安排You many depend upon it that we shall never lose heart.你放心我们绝不会气馁Id appreciate it if you would like to teach me how to use the computer.句型为句型为appreciate/like/love/hate+it+if/that/wh-从句从句第27页it作主题强调句作主题强调句it作主题强调句为：it is/was+被强调部分+that/who+其余部分被强调部分能够是原来句子主语，宾语，主语或宾语补足语，状语。强调假如是原因状语从句，只能由because引导，不能由since，as或why引导。不能被强调部分是表语、谓语动词或though/although等引导让步状从第28页1.当被强调是主语，主语是人时，可用当被强调是主语，主语是人时，可用who或或that等引发后面部分，不然用等引发后面部分，不然用that；被强调是主语，要使用主格被强调是主语，要使用主格John might have bought a new book for Mary yesterday.It is John who/that have bought a new book for Mary yesterday.(强调主语)It was she who/that suggested that he go to New York in order to get a direct flight.第29页2.当被强调时宾语，宾语时人时，可用当被强调时宾语，宾语时人时，可用whom或或that引发后面部分；被强调是物时，用引发后面部分；被强调是物时，用that或或which（不常见）（不常见）John might have bought a new book for Mary yesterday.It is a new book that/which John might have bought for Mary yesterday.It is this novel that/which they talked about last week.It is where the meeting will be held tha we want to know.(强调宾从)第30页3.当被强调是主语补足语或宾语补足语时，当被强调是主语补足语或宾语补足语时，用用that引发后面部分引发后面部分It is Iron Man that he is called.(强调主补)It was chairman of the committee that we elected her.（强调宾补）It is red that he has painted the door.（强调宾补）第31页4.当被强调是状语时，用当被强调是状语时，用that引发后面部引发后面部分，而不用分，而不用when或或where等等It is for Mary that John might have bought a new book yesterday.(强调状语)It was because the water had risen that they could not cross the river.(原因状从)It was yesterday that I met him in the street.(时间状从)It was at an evening party that I first saw her.(地点状从)第32页5.“not.until”结构中强调形式结构中强调形式It is/was not until.that.My father didnt come home until 12 last night.It was not until 12 last night that my father came home.I didnt know it until he told me.It was not until he told that I knew it.第33页6.It is.that强调句疑问句强调句疑问句普通疑问句把is/was提前Was it she that broke the window yesterday?特殊疑问句要在普通疑问句前加上特殊疑问词Why is it that silver is not widely used as conductor?Why is silver not widely used as conductor?(非强调句型)When and where was it that you got to know Professor Smith?What kind of work is it tht you want?第34页7.有时可用有时可用It might be.that.;It must have been.that.句型表强调句型表强调It might be a teacher that he is now.It must have been because I was new that they distrusted me.It must have been Mary whose brother helped me with my luggage.第35页8.强调句型与其它句型区分强调句型与其它句型区分强调句型去掉It is/was.who/that之后，句子结构依旧完整，去掉之后不完整可能是主从，定从或其它从句。被强调部分译成汉语时，也要译成被强调部分。无法这么翻译就不是强调句It is the ability to do the job that matters not where you come from or what you are.(去掉后)The ability to do the job,not where you come from or what you are,matters.第36页Thank you for watching第37页