whether和if的用法区别(共102页).doc

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1、精选优质文档-倾情为你奉上whether和if的用法区别whether与if作“是否”讲，在用法上有相同之处，也有不同之处。 一、相同之处。 1.whether和if都能引导宾语从句，常置于see,ask,learn,tell,wonder,doubt,find out等动词之后。 如：He asked me whether/is I could help him. I want to know whether/if he lives there. 2.whether和if都可用it作形式主语从句中。如： its uncertain whether/if hell come this even

2、ing. 3.在be uncertain/doubtful之后，常用whether引导宾语从句，有时也可以用if，如： We are uncertain whether/if Mary will come. 二、不同之处。 1.whether可置于句首引导主语从句，而if不能。如： _the 2000 Olympic Games will be in Beijing is not known yet. A.whether B.If C.Whether D.That 答案是C。 2.whether可用在介词之后，引导宾语从句，而If则不能。如： Success depends on whethe

3、r we make evough effort. 3.whether可引导表语从句，if则不能。如： The puestion is whether it is not worth doing. 4.在名词之后引导同位语从句时，用whether而不用if。如： The question whether the students answered correctly should be decided by the teacher. 5.whether后可接不定式，而if不能。如： Please tell us whether to go or stay here. 6.在有些动词（如discu

4、ss）之后，只能用whether，而不用if引导宾语从句。如： We discussed whether we should close the shop. 7.在引导否定概念in宾语从句时，只能用if，而不用whether.如：he asked me if I hadnt finished my work. 英语时态 一般现在时表示现在、经常或习惯的动作或状态和普遍现象、常识或客观真理；一般过去时用于过去某一时间内发生的或过去习惯性的动作或状态；一般将来时表示将要发生的动作或存在的状态，将来打算做的事情；现在完成时表示过去发生的动作造成目前的结果和对现在造成的影响或表示从过去延续至今的动作、

5、状态和习惯等；将来完成时表示将来某时之前业已完成或发生的事情；过去完成时表示过去某时间之前已经发生的动作或状况，即过去的过去。注意每一种时态与其他时态的交叉使用情况。英语共有十六种时态，其表现形式如下(以study为例)：一般时 进行时 完成时 完成进行时 现在 study studies am studying is studying are studying have studied has studied have been studying has been studying 过去 studied was studying were studying had studied had b

6、een studying 将来 shall study will study shall be studying will be studying shall have studiedwill have studied shall have been studying will have been studying 过去将来 should study would study should be studying would be studying should have studied would have studied should have been studying would hav

7、e been studying 但考试中出现的一般有以下几种。第一节 一般现在时一、表示一般性或经常发生的动作或状态二、表示习惯性动作和状态或普遍的现象或常识三、表示客观事实、客观规律和客观真理。在宾语从句中，即使主句的谓语动词用了过去时，只要从句表示的是客观真理，从句的谓语动词也要用一般现在时四、祈使句必须用动词原形，其否定结构用“dont动词原形”，如：Go and fetch some water. Dont do that.五、在反义疑问句中，如果主句用肯定句，那么，反问句用否定形式；如果主句用否定形式，那么，反问句就用肯定形式。而且前后在时态上要一致。但祈使疑问句用wont you?

8、进行反问。如：See a film tonight, wont you?注： 祈使句后边可用附加疑问句，以加强语气。如果祈使句用肯定形式，附加疑问句用否定形式；如果祈使句用否定形式，附加句用肯定形式；如： Come here next Sunday, wont you? Dont tell it to anyone, will you? 但如果祈使句的前一句有了表示强烈肯定的语言环境，即使祈使句用了肯定形式，其附加成分也可以用“will you”(表示肯定，如果是在口语中用降调)。如：Give me the book, will you? 第二节 一般过去时一、一般过去时主要表示过去某一时刻发

9、生的动作或情况，句中通常有表示过去某一时刻的状语 a day ago, last week, in 1996, during the night, in anceint times等，表示“过多少时间之后”用after, 但在现在完成时中用in, 如in the past few years等第三节 一般将来时一、一般将来时表示将要发生的动作或状况二、在表示时间和条件的状语从句中，一般现在时代替一般将来时。这些时间副词有when, as soon as等，表示条件的连词有if,as long as等三、一些表示方向及变化的瞬间动词可用进行时或现在时表示将要发生的动作We leave (are

10、leaving) for California the day after tomorrow.我们(计划)后天动身去加利福尼亚州。May I have your attention please. The plane for Wuhan is about to take off.请注意，飞往武汉的飞机就要起飞了。四、另外，“be +to 动词原形”也可表示打算做的事，还可表示责任、意向和可能性You are to follow the doctors advice.你应遵从医嘱。No shelter was to be seen.找不到避难处。 第四节 现在完成时一、现在完成时的构成式是hav

11、e(has)动词的ED分词二、现在完成时表示到现在为止的一段时间内发生的情况或动作，强调的是对现在的影响，可能是已完成的动作，也可表示多次动作的总和，或习惯性的行为和持续的动作三、如果句中有表示到现在为止这段时间的状语时，用现在完成时，这些时间状语有 now, today, this week, this month, this year，现在完成时不和表示具体的时间状语连用，如yesterday, last year等，但可以和always, before, just, induring the past(few weeks, years, fifty years)连用，这时in表示“过去多

12、少时间”，不能用after四、在有already, as yet, yet, ever, just, never 这类副词作状语的情况下，用现在完成时五、有“since时间点，for一段时间”引导的状语时，主句谓语用现在完成时态11) Jekyll Island has been one A of Georgias state B parks C in D 1954.12) He is A in this country now B for five years， but he makes C no attempt to speak D our language.13) The Browns

13、A are living a hard B life because Mr. Brown has been unemployed C since D half a year.六、现在完成时用于将来的情况，即主语为一般将来时，时间和条件从句中的谓语用现在完成时(而不能用将来完成时)表示将来某时完成的动作第五节 将来完成时和过去完成时一、将来完成时表示将来某时业已发生的动作和情况，或已经存在的状态二、过去完成时表示在过去某一时刻之前业已发生了的动作或现象，句中通常会出现有表示过去某一时刻的时间状语第六节 进 行 时 态一、现在进行时表示现在或现阶段进行的动作，但也和always, constant

14、ly, forever等频度副词连用表示一个经常进行的动作或现在存在的状态二、瞬间动词和一些表示状态及感觉的动词一般不用进行时，而用一般现在时或一般过去时代替。这些动词包括：appear(显然), arrive, be, come, desire, go, find, hate, hope, join, know, leave, like, love, join, possess, start, sail, see, suggest, taste, think(认为), understand等，类似的动词还有belong to， consist of，seem(似乎)等三、过去完成进行时过去完

15、成进行时表示到过去的某一时间点或某一时间段里一直在进行的动作或行为5) They received the parcel that they for a long time.A expected B have expected C had been expecting D had expectedThere is a wellknown incident in one of Molieres plays, where the author makes the hero express unbounded delight on being told that he had been talkin

16、g prose during the whole of his life.(93年翻译)四、例题解析1) D错。slow只有作为不及物动词用时才与up或down连用，表示“慢慢向上”或“慢慢向下”。所以我们说，这里的slow是动词而不是形容词，应将动词slow后边加上“ing”，改为(is) slowing down，构成现在进行时。2) C错，改为are。3) A错，改为saw。4) D错，改为are。5) C为正确答案。 英语高考专题复习讲与练（17）反意疑问句反意疑问句是英语四大问句之一，它是由一个陈述句加上一个短问句而构成的。反意疑问句的基本构成形式是：陈述句+动词（肯定或否定）+主语

17、？如： She often has lunch at school, doesnt she? You dont like sports, do you? 使用反意疑问句要注意以下若干对应规则： 一、 反意疑问句中问句部分的动词与陈述部分的动词在语气上成相反的对应关系，即： 肯定+否定？ 否定+肯定？如： You cant do it, can you? They are very late for the meeting, arent they? 二、 反意疑问句中问句部分的动词与陈述部分的动词种类要对应一致。如： He has supper at home every day, doesnt

18、 he? （不能用hasnt he?） They have known the matter, havent they? （不能用dont they?） 三、 反意疑问句中问句部分的动词在时态上应和陈述部分的时态一致。如： They will go to town soon, wont they?（不能用dont they?或 arent they?） He works very hard, doesnt he?（不能用didnt he?或wont he?） 四、 反意疑问句的陈述部分含有由un-, im-, in-, dis-, 等否定意义的前缀构成的词语时，陈述部分要视为肯定含义，问句部分

19、用否定形式。如： Your father is unhappy, isnt he?（不能用is he?） The man is dishonest, isnt he? （不能用is he?） It is impossible to learn English without remembering more words, isnt it?（不能用is it ?） 五、反意疑问句的陈述部分带有little, few, never, hardly, seldom等否定意义的词时，问句部分用肯定式。如： She never tells a lie, does she?（不用doesnt she?）

20、He was seldom late, was he?（不用wasnt he?） 六、反意疑问句的陈述部分为I am时，问句部分习惯上用arent I？表示。如： I am a very honest man, arent I? 七、反意疑问句的陈述部分为I(We) think(believe, suppose, consider) + that从句时，问句部分的动词及主语与that从句内的动词和主语保持一致。如： I think that he has done his best, hasnt he? We think that English is very useful, isnt it

21、? （不用dont we?） 八、反意疑问句的陈述部分为I(We) dont think(believe, suppose, consider)+ that从句时，从句为否定意义，问句部分的动词和主语仍与that从句保持一致且用肯定式。如： I dont think that you can do it, can you? （不用do I?） We dont believe that the news is true, is it? （不用do we?） 九、反意疑问句的陈述部分为非第一人称主语+ think(believe, suppose, consider) + that从句时，问句部分

22、的动词和主语与陈述部分的主句动词和主语保持一致。如： They all think that English is very important, dont they? （不用isnt it?） He didnt think that the news was true, did he? （不用wasnt/ was it?） 十、反意疑问句的陈述部分为主语+said( told, reported, asked) + that从句时，问句部分的动词和主语与陈述部分的主句动词和主语保持一致。如： They said that you had finished your work, didnt t

23、hey? （不用hadnt you） Kate told you that she would go there, didnt she? （不用wouldnt she?） 十一、陈述部分的主语为不定代词something, anything, nothing, everything时，问句部分的主语用it。如： Something is wrong with the computer, isnt it?Nothing has happened to them, has it? 十二、陈述部分的主语为不定代词somebody(someone), anybody(anyone), nobody(n

24、o one), everybody(everyone)时，问句部分的主语用he或 they，这时问句动词的数应和he或 they一致。如： Someone has taken the seat, hasnt he?Everyone has done their best in the game, havent they? 十三、陈述部分为Let me时，问句部分习惯上用shall I? 或will you?形式。如： Let me have a try, shall I?(will you?) 十四、陈述部分为Let us时，问句部分习惯上用will you?形式。如： Let us stop

25、 to rest, will you? 十五、陈述部分为Lets时，问句部分习惯上用shall we?形式。如： Lets go home together, shall we? 十六、陈述部分用上述情况以外的祈使句时，问句部分一般用will you?形式表示请求，用wont you？形式表示委婉请求或邀请。如： Do sit down, wont you?/ will you? You feed the bird today, will you? Please open the window, will you?(wont you?) 十七、陈述部分为否定祈使句时，问句部分一般用will y

26、ou?形式。如： Dont make any noise, will you? 十八、陈述部分为There (Here) + be + 主语时，问句部分用动词+there(here)?形式。如： There are two cakes on the plate, arent there? Here is a story about Mark Twain, isnt here? 十九、陈述部分用had better +原形动词表示建议时，问句部分用hadnt +主语？形式。 Youd better tell him about the matter, hadnt you?We had bette

27、r do it by ourselves, hadnt we? 二十、陈述部分用used to +主语时，问句部分用didnt + 主语？或usednt +主语？形式。 He used to live in the country, didnt he?/usednt he? They used to be good friends, didnt they?/usednt they? 二十一、陈述部分用must(may, might) + have + V-ed表示推测时，若句中带有明显的过去时间的状语，问句部分动词用过去时形式。如： He might have forgotten his pe

28、n in the classroom yesterday, didnt he? （不用mightnt he?/ hasnt he?） You must have got up late this morning, didnt you?（不用mustnt you?/havent you?） 二十二、陈述部分用must(may, might) + have + V-ed表示推测时，若句中没有带明显的过去时间的状语，问句部分动词用现在完成时形式。如： Everyone must have known the death of the waitress, havent they? （不用mustnt

29、they?） You must have worked there a year ago, didnt you?（不用mustnt you?/ havent you?） 二十三、陈述部分的主语为从句时，问句部分的主语一般用it代替，如： What he said is true, isnt it? （不用didnt he?） Where we will build the dam has not been decided yet, has it? （不用wont we?） 二十四、陈述部分的主语为动名词或不定式时，问句的主语用it代替。如： To do one good deed is eas

30、y for a person, isnt it?Skating is your favorite sport, isnt it? 反意疑问句专题练习 1.I think they will go to town tomorrow, _? A.do I B.dont I C.will they D.wont they 2.I dont believe he can catch up with me, _? A.can he B.cant he C.do I D.dont I 3.Im sure that I will be well again, _? A.am I B.arent I C.wi

31、ll I D.wont I 4.I am afraid that he will not come, _? A.am I B.arent I C.will he D.wont he 5.They dont believe you are wrong, _? A.are you B.arent you C.do they D.dont they 6.He thought you were Beijing, _? A.didnt he B.did he C.werent you D.were you 7.We told you that he would come tonight, _? A.di

32、dnt we B.did we C.would he D.wouldnt he 8.The reporter said the news was not true, _? A.wasnt it B.didnt he C.did he D.was it 9.They suggested that he should go to work at once, _? A.did they B.didnt they C.should he D.shouldnt he 10.Your brother has lunch at home, _-? A.hasnt he B.doesnt he C.has h

33、e D.does he 11.John has to get up early, _? A.has he B.hasnt he C.does he D.doesnt he 12.She has got to get everything ready, _? A.hasnt she B.has she C.doesnt she D.does she 13.She has never been to China, _?A.has she B.hasnt she C.doesnt she D.does she 14.She had better tell you the news right now

34、, _? A.had she B.hadnt she C.did she D.didnt she 15.They would rather not have done that last week,_? A.would they B.wouldnt they C.have they D.havent they 16.Id rather stay here for a rest, _?A.did I B.would I C.didnt I D.wouldnt I 17.You ought to do it again,_?A.ought you B.oughtnt you C.do you D.

35、dont you 18.You must do that again,_?A.mustnt you B.neednt you C.do you D.dont you 19.He must wait here, _?A.mustnt he B.doesnt he C.shouldnt he D.does he 20.He must be a good worker,_?A.mustnt he B.neednt he C.isnt he D.doesnt he 21.He must have been to China twice,_? A.hasnt he B.didnt he C.wasnt

36、he D.mustnt he 22.He must have been ill last week,_? A.hasnt he B.didnt he C.wasnt he D.mustnt he 23.He must have known you during the war,_? A.hasnt he B.didnt he C.wasnt he D.mustnt he 24.He must have known the result already,_? A.hasnt he B.didnt he C.wasnt he D.mustnt he 25.There used to be a te

37、mple here,_? A.didnt there B.did there C.used there D.was there 26.They used to be good friends,_? A.usednt they B.didnt they C.used they D.both A and B 27.Mother usednt to dress the baby,_? A.didnt she B.did she C.used she D.usednt she 28.The students used to go to see him,_? A.usednt they B.didnt

38、they C.used they D.both A and B 29.Alice, you have a little more chicken,_? A.havent you B.dont you C.will you D.do you 30.Hi! Alice, you have bought a little chicken,_? A.havent you B.wont you C.will you D.have you 31.You two had breakfast just now,_? A.hadnt you B.didnt you C.had you D.did you 32.

39、You two had finished the breakfast,_? A.hadnt you B.didnt you C.did you D.had you 33.Neither you nor I was invited to the party,_? A.were we B.werent we C.was I D.were you 34.Either he or she is to clean the window,_? A.are they B.arent they C.isnt he D.isnt she 35.It is Jiao Yulu who turned Lankao

40、into a rich district,_? A.is it B.isnt it C.did he D.didnt he 36.It was you who never made such mistakes,_? A.wasnt it B.werent you C.did you D.didnt you 37.The little child dared not climb the tree,_? A.dared he B.did he C.was he D.does he 38.What he said is not wrong,_? A.didnt he B.did he C.is it

41、 D.isnt it 39.That his parents were ill made him a little worried,_? A.werent they B.were they C.didnt it D.wasnt it 40.He dislikes what you have said,_?A.does he B.doesnt he C.have you D.havent you 41.(2003Shanghai spring)If you want helpmoney or anything,let me know,_you? A.dont B.will C.shall D.d

42、o 42.(2002Shanghai)Mrs. Black doesnt believe her son is able to design a digital cameral,_? A.is he B.isnt he C.doesnt she D.does she 43.(2002Shanghai spring)Brian told you that there wasnt anyone in the room at that time,_? A.was there B.wasnt there C.didnt he D.did he 44.(2001Shanghai)I dont suppo

43、se anyone will volunteer,_? A.do I B.dont I C.will they D.wont they 45.(2000Shanghai)The news that they fialed their driving test discouraged him,_? A.did they B.didnt they C.did it D.didnt it 46.(NMET99)Alice,you feed the bird today,_? -But I fed it yesterday. A.do you B.will you C.didnt you D.dont

44、 you 虚拟语气 有些条件句是可能实现的,称为真实条件句. 虚拟语气是动词的一种特殊形式,用来表达说话人的意愿.请求,设想,等未能或不可能实现的事实,或说话人看来实现可能性很小的情况.做这类题时首先要弄清楚虚拟语气的各种句型,即由if引导的虚拟条件句,省略if的倒装形式,可跟虚拟语气的宾语从句,同位语从句,表语从句的句型,以及表示祝愿或感叹的句子和由without, but for等介词引导的短语或句子. 高考对虚拟语气的测试主要涉及以下方面: 1). 主语从句,同位语从句中虚拟语气的用法. 2). 宾语从句中虚拟语气的用法,尤其是wish 虚拟语气结构的用法. 3). If条件句中虚拟语气

45、的用法,应特别注意省略if的倒装结构是考试的重点. 4). would rather 等结构中虚拟语气的用法. 5). if only结构中虚拟语气的用法. 6). But, or, otherwise 等含蓄条件句的用法. 7). Its time (that) 等结构中虚拟语气的用法. 1. 虚拟语气在虚拟条件句中的运用 (1)虚拟语气现在时. 用以表示与现在事实相反的假设或现在实现可能性不大的情况. 条件从句 主句 动词过去式(be多用were) Would/should/could/might + 动词原形 Eg. If I were a bird, I would fly to yo

46、u. If it were not for their help, we should be in a very difficult position. (2) 虚拟语气过去式. 表示与过去事实完全相反的假设. 条件从句 主句 had + 过去分词 would/should/could/might + have +过去分词 Eg. If we had started earlier, we should not have missed the train. If she hadnt been ill, she might have come. (3)虚拟语气将来式. 表与将来情形相反的假设或极