it作形式主语ppt课件.ppt

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1、,以形式主语it引导的句型,为避免主语冗长,句子头重脚轻,经常用it作形式主语,主语从句放在后面作真正的主语。,1. It is certain that he will succeed.2. It is not known whether he will go there.3. It has not been decided yet when theyll start the project.,“It” is used as empty subject.,形式主语,1. It is 名词 从句 It is a fact that 事实是 It is an honor that 非常荣幸 It

2、 is common knowledge that 是常识能获邀参加你们的婚礼真是不胜荣幸风就是流动的空气,这是常识可惜他由于一个拼写错误没有得满分,Its a great honor that I have been invited to your wedding.,Its common knowledge that wind is moving/flowing air.,Its a pity that he didnt get full marks because of a spelling mistake.,句型1.,2. It is + adj. +从句 Its certain tha

3、t 肯定 It is possible that. 很可能 It is unlikely that. 不可能 It is obvious that 很明显 It is necessary important natural. that*_(很可能)she will come back tomorrow.*_(很明显)this measure is effective.,+(should) +do,It is possible that,It is obvious that,句型2.,另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用 虚拟语气 “(should) +d

4、o”，常用的句型有： It is necessary (important, natural, strange, etc.) that It is suggested (requested, proposed, desired, etc.) that,3. It happens (seems, looks, appears ) that.该句型中it是形式主语，that 引导的是主语从句,主句中的happen, seem 等词是不及物动词,It happened ( so happened ) that he met his teacher in the street. 碰巧It seems

5、that he will be back in a few days.,句型3.,Itseemsthatsb.do/bedoing/havedone/haddone=Sb.seemstodo/bedoing/havedone/tobedone/tohavebeen,ItseemedthathehadbeentoBeijingbefore .=HeseemedtohavebeentoBeijingbefore.,It +不及物动词+从句 It happened that. 碰巧 It occurred to me that我突然想起*_(刚好)I came into the office at

6、that time.*_(我突然想起)I forget to sent the letter.,It happened that,It occurred to me that,句型4.,据说他读过这篇小说,.,Itwassaidthathehadreadthisnovel .=Hewassaidtohavereadthisnovel.,It + be + -ed 分词+ that-从句It is said that 据说It is known that 据了解It is reported that据报道It is believed that据认为,据说她两年前在美国留学 Its said th

7、at he studied in America two years ago2. 据说她现在正在美国留学 Its said that he is now studying in America 3.据说她现在懂三国外语 Its said that he knows three foreign languages,He is said to have studied in America two years ago.He is said to be studying in America now.He is said to know three foreign languages.,It is

8、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.,注意,It is doubtful whether she will be able to co

9、me她是否能来还不还说。It was clear enough what she meant.她的意思还不太清楚。It wont make too much difference whether he will join us.他是否参加我们队不会太重要。Has it been found out who set the record? 是谁破了纪录弄清楚了吗？,5、可用whether和疑问词引导从句的有： It is doubtful (not known, not decided, not made clear, to be found out, being considered, a m

10、ystery, a question, + that/whether,句型5,It is still a question when we shall have our sports meeting. It is a mystery to me how it all happened.这事是怎么发生的还是个谜。It hasnt made clear when the new road is to be opened to traffic.新路什么时候通车还不清楚。,6. It doesnt matter how/ whether ( if ) 结构中的主语从句不可提前。 该句型中whether

11、 (if) 引导的从句是真正主语，该句型常译为“不论（是否） 没关系。,It doesnt matter if they are old. It doesnt matter who will go instead of me.谁代替我去不重要。,句型6,It doesnt matter whether he is wrong or not. (right)Whether he is wrong or not doesnt matter. (wrong),该句型是强调句型。被强调部分可以是主语，宾语，表语或状语。强调的主语如果是人，that 可以由 who 换用。,It was about 60

12、0 years ago that the first clock was made. It was they that (who ) cleaned the classroom yesterday. It was in the street that I met her father.,7. It is + 被强调部分 + that .,1.正确选用is 或was.2. 强调部分是人，可以用who.3. 强调主语，that 或who 后面的谓语形式与主语一致不能强调谓语,注意,8. It is not until + 被强调部分 + that . 该句型也是强调句型。主要用于强凋时间状语，译成

13、汉语 “直到才”，可以说是 not . until . 的强调形式。,=It was not until she took off her dark glasses that I realized she was a famous film star.,I didnt realize she was a famous film star until she took off her dark glasses.,= Not until she took off her dark glasses did I realize she was a famous film star.,9. It is

14、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.,10. It is since . 该句型主要

15、用作处理瞬间动词的完成时，又要和表示一段时间的时间状语连用的问题。主句中是时间作表语，其时态是现在时或完成时，since 引导的从句通常是一般过去时态，而且是瞬间动词。如果主句是一般过去时，从句则用过去完成时。,It is ( has been ) 5 years since his father died.,It was 1949 when I was born.,It was in 1949 that I was born.,区别句下面这个句子：,11. It is . when . 该句型中的 when 引导的是一个时间状语从句，主句中的 it 指时间，表语由具体的时间充当。常译为“当的

16、时候，是”。,It was 5 oclock when he came here.,强调句型,时间状语从句,12. It be . before .该句型主句中的 it 指时间, 主句中的时态常是一般将来时或过去时两种时态主句中的表语多是long, not long , 3 days , 2 weeks 等表示时间段的词或短语。常译为“之后”。,It was 3 days before he went to Beijing. It will be not long before he finishes his job.,要过好几个月她才会适应这项工作,It will be months bef

17、ore she is fit for the job.,过了一星期他回来了,It was a week before he came back.,过了不久，她认识到她错了,It was not long before she realized she was wrong.,他离开中国已经10年了,It is 10 years since he left China.,如以过去某一时间为基点，则为：It was 10 years since He had left China.,区别句意：,It is three years since I lived here.It is three year

18、s since I have lived here.It is three years since I began to live here.,我不住在这里已经有三年了。,后两句的含义是：我住在这里已经有三年了。,It is + 段时间 + since. / It has been + 段时间 + since.表示“从起已有多长时间了” 。,It is three years since he smoked. 他不吸烟已有 3 年了。 试比较：It is three years since he began to smoke. It is three years since he has sm

19、oked. 两句均意为：他吸烟已有 3 年了。,用法：since 从句中常用一般过去时，(1)若从句中是持续性动词的一般过去时， 则表示该动作结束有多长时间 了则翻译为“已经不再多长时间了”； ，(2)若是短暂性动词，的一般过去时，则表示该动作发生后，距离现在有多长时间了则翻译为“已经.多长时间了” (3)若是持续性动词的现在完成时， 则表示动作和状态延续到现在 (说话时刻)， 其表示的时间的起点应从动作发生之时算起。,注意：在这种结构中， since 引导的从句绝对不能用否定式的谓语动词来表示否定意义。,他好久没学汉语了。 误：It is a long time since he didnt

20、 study Chinese. 正：Its a long time since he studied Chinese. (studied 为持续性动词， 应从其动作结束时算起),It is three years since I was a college student.,我已经毕业三年了。,It is three years since I became/have been a college student.,我成为一名大学生已经两年了,13. It takes sb. to do sth.该句型中的不定式是真正的主语，it是形式主语，句型中的直接宾语是时间。常译为“做要花费某人”。,I

21、t took thousands of people many years to build the Great Wall.,14. It is no good (use ) doing sth.该句型中的真正主语是动名词短语，主句中的表语可以是no good , ( not any good ) , no use , ( not any use )。,It is no good learning English without speaking English.,It is no use for him to learn English without speaking it.,15. It

22、 looks ( seems ) as if . 该句型中it 无意义。 as if 引导一个状语从句。常译为，“看起来好象 如果与事实不相符合，则用虚拟语气,It looks as if he is ill.（真的病了） It looks as if he were ill. （没有生病） It seemed as if he were dying.,16. It is kind ( of sb. ) to do sth.该句型中的不定式短语是真正主语，如果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形容词。常见的有: bad, brave, careless,

23、 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.,It is kind of you to say so. = You are kind to say so.,17. It is necessary ( for sb. ) to do sth. 该句型与上一个同属一个句型。如果不定式的逻辑主

24、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,安全等情况的形容词。常见的形容词有：, important, necessary, natural easy, safe, common, normal, hard, difficult, dangerous, unusual, rare, impossible, pleasant 等。,在中的形容词作表语可以用从句改写，如：,It is important for her to come to the party. = It is important that she (should ) come to the pa

25、rty,主语从句不可位于句首的五种情况：,（1）if 引导的主语从句不可居于复合句句首。（2）It is said /reported结构中的主语从句不可提前。例如： It is said that President Jiang will visit our school next week. That President Jiang will visit our school next week is said. （3）It happens/occurs结构中的主语从句不可提前。例如： It occurred to him that he failed in the examination

26、. That he failed in the examination occurred to him.,(5) 含主语从句的复合句是疑问句时，主语从句不可提前。例如：,Is it likely that it will rain in the evening? (right)Is that it will rain in the evening likely? (wrong),（4）It doesnt matter how/whether 结构中的主语从句不可提前。例如： It doesnt matter whether he is wrong or not. Whether he is w

27、rong or not doesnt matter.,1.It now appears _ they are in need of help. A. that B. which C. what D. how2.It is good news _ they will arrive in a few days. A. which B. what C. that D. how3.It _ Joe drives badly. A. thought that B. thinks that C. is thought D. is thought that,4.I have always been hone

28、st and straightforward, and it doesnt matter _that Im talking to.A. who is it B. who it is C. it is who D. it is whom,5. It is pretty well understood _ controls the flow of carbon dioxide in and out the atmosphere today. A. that B. when C. what D. how,选C，从句缺少主语，what正好可以作为主语，意思大家知道是什么控制着二氧化碳进出大气层。,6.

29、It is important that _ our education in all available ways. A. we must develop B. we shall develop C. we would develop D. we should develop7.It is necessary that _ by the end of the week. A. we got everything ready B. we have got everything ready C. We get everything ready D. we must get everything

30、ready 8.It was natural that _. A. my pictures would surprise them B. my pictures surprised them C. my pictures should surprise them D. my pictures would have surprised them9.I wonder _. A. whether or not Ill catch the last bus B. if or not Ill catch the last bus C. that Ill catch the last bus or not

31、 D. that Ill catch the last bus,10. _ made the school proud was_ more than 90 of the students had been admitted to key universities. A. What; because B. What ; thatC. That ; what D. That ; because,意思：令这所学校骄傲的是90的学生都被重点大学录取了,B 是个主语从句 和表语从句,11. _ we will go camping tomorrow depends on the weather. A.

32、If B. Whether C. That D. Where12. _ that they can pass the written exam this time. A. That is hoped B. It is hoped C. It hopes D. That hopes,13. _ leaves the room last ought to turn off the lights. A. Anyone B. The person C. Whoever D. Who,14. _ is a fact that English is being accepted as an interna

33、tional language. A. There B. This C. That D. It,C,D,15. _ in the newspaper that the price of food will go up. A. It says B. It is said C. It has said D. He is said,16. It worried her a bit _her hair was turning grey. A. while B. that C. if D. for,B,B,17. The Foreign Minister said, “_ our hope that t

34、he two sides will work towards peace.” A. This is B. There is C. That is D. It is,D,18. It is necessary that a college student _ at least a foreign language. A. masters B. should master C. mastered D. will master,B,19. _ his dream of going to college will come true is uncertain.That B. Whether C. If

35、 D. Even if20. It is known to us _ where there is pollution, there is harm.A. which B. where C. what D. that,21. - I saw your neighbor break your window with a basketball. - _ it made me nearly mad. A. That he broke B. What he broke C. He broke D. His break22.It remains a question _ we can get so mu

36、ch money in such a short time. A.how B. that C. when D. what,汉译英,1.很遗憾我们输了这场比赛。2 他在考试中作弊是事实。3 这幅画好像挂倒了 (appear)4 车祸发生的时候碰巧我在我的一个朋友散步 (happen)5 今年这所大学将招收更多的新生是真的 6 知识就是力量,这一点是不言而喻的clear7一般认为,印第安人是美洲大陆最早的居民8学会处理各种挑战对我们来说是很有必要的,homework,这样就构成了下面一些常用句型: 1) It is + n. +从句 It is a pity/shame that. 遗憾的是 It

37、 is a surprise that令人惊奇的是 It is a fact that 是事实 It is common knowledge that 是常识*1_(很遗憾)we lost the match.2 _(这是事实)he cheated in the exam.,It is a pity that,It is a fact that,3 这幅画好像倒挂了 (appear)4车祸发生的时候碰巧我在我的一个朋友散步 (happen),It appears that this picture hangs upside down,It happened that I was walking

38、 with one of my friends when the car accident occurred,I happened to be walking with one of my friends when the car accident occurred,5 今年这所大学将招收更多的新生是真的 6 知识就是力量,这一点是不言而喻的8学会处理生活中的各种挑战对我们来说是很有必要的,Its true that the university will enroll more new students (freshmen),Its clear that knowledge is power,Its necessary that we should learn how to deal with various challenges.,7 一般认为,印第安人是美洲大陆最早的居,Its generally believed that Indians are the first settlers in American continent.,