as if 的用法.doc

as if 的用法 as if 好像，好似 She spoke to me as if she knew me. 她和我说话的神情，好像她早就认识我似的。 (= as though) as if 的用法 一、as if 从句的作用 1 在look, seem 等系动词后引导表语从句。如： She looks as if she were ten years younger 她看起来好像年轻了十岁。 It seems as if our team is going to win 看来我们队要胜了。 2 引导方式状语从句。如： She loves the boy as if she were his mother 她爱这男孩，就好像她是他的母亲一样。 The child talked to us as if he were a grownup 那孩子跟我们谈起话来，像个成年人似的。 二、as if 还可用于省略句中 如果as if 引导的从句是“主语系动词”结构，可省略主语和系动词，这样as if 后就只剩下名词、不定式、形容词（短语）、介词短语或分词。如： He acts as if （he was） a fool 他做事像个傻子。 Tom raised his hands as if （he was going） to say something 汤姆举起手好像要说什么。 She left the room hurriedly as if （she was）angry 她匆忙离开房间好像生气的样子。 三、as if 从句的语气及时态 1 as if 从句用陈述语气的情况。 当说话者认为句子所述的是真实的或极有可能发生或存在的事实时。如： It sounds as if it is raining 听起来像是在下雨。 He talks as if he is drunk 从他谈话的样子来看他是醉了。 2 as if 从句用虚拟语气的情况。 当说话人认为句子所述的是不真实的或极少有可能发生或存在的情况时。从句虚拟语气动词时态的形式如下： （1）如果从句表示与现在事实相反，谓语动词用一般过去时。如： You look as if you didn t care 你看上去好像并不在乎。 He talks as if he knew where she was 他说话的样子，好像他知道她在哪里似的。 （2）从句表示与过去事实相反，谓语动词用“had过去分词”。如： He talks about Rome as if he had been there before 他说起罗马来好像他以前去过罗马似的。 The girl listened as if she had been turned to stone 那女孩倾听着，一动也不动，像已经变成了石头似的。 （3）从句表示与将来事实相反，谓语动词用“wouldcouldmight动词原形”。如： He opened his mouth as if he would say something 他张开嘴好像要说什么。 It looks as if it might snow 看来好像要下雪了。whether和if的用法分析 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 evening. 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 whether 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discuss）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. ; whether和if都可以引导宾语从句，表示“是否”，在口语或间接引语中两者可以互换使用。如： I wonder if / whether I can get some advice from you. Ask him whether / if he can come. 但在有些情况下，whether和if的用法有一定区别。 1. whether引导的从句常可以与连词or或or not直接连用，而if一般不能。如： 正： Let me know whether you can come or not. 误： Let me know if you can come or not. 2. 当宾语从句提到句首时，只能用whether引导，而不能用if。如： 正： Whether it is true or not, I cant tell. 误： If it is true or not, I cant tell. 3. whether可以引导带to的不定式，if则不能。如： 正： I dont know whether to accept or refuse. 误： I dont know if to accept or refuse. 4. whether及其引导的成分可放于介词之后，作介词的宾语，但if不能。如： 正： I worry about whether I hurt her feelings. 误： I worry about if I hurt her feelings. 5. whether可以引导从句，作主语、表语或同位语，而if不能。如： 正： It was uncertain whether he would come. 误： It was uncertain if he would come. 正： His first question was whether Tom had arrived yet. 误： His first question was if Tom had arrived yet. 正： We must consider the question whether we will take these measures. 误： We must consider the question if we will take these measures.in case 后面跟从句，从句用一般现在时，或用should型虚拟语气，按英语老师讲两者通用in case万一。是连词，引导条件状语从句。也就是说in case后面是一个完整的句子 Take a hat with you in case the sun is very hot. 倘若太阳很利害，你就把帽子戴上。 in case of的of是介词，介词后面只能带名词性质的词，比如名词、代词等。意思和in case差不多，万一的意思 In case of rain they cant go. 万一下雨，他们就不能去了。 in the case of，就.来说, 关于。意思跟上面两个不一样了。一般表示转而提及另一件事情。比如 In the case of woman，they have more difficulty in their job。就女性来说，她们在工作中会遇到更多的困难 1. We have an auxiliary generator in case of power cuts. 我们有一台万一断电时使用的备用发电机。 2. In case you need something, please dont hesitate to let me know. 如果你需要什么东西，请不客气地对我说。 3. It may rain youd better take an umbrella (just) in case (it does). 可能下雨-你最好带把伞, 以防万一（下起来）. 4. In case that he leaves, please inform me. 如果他离开, 请通知我。 5. In case of rain, they cant go. 万一下雨，他们就不能去了。 6. In case (=If) I forget, please remind me. 万一我忘记，请提醒我。 7. Write the telephone number down in case you forget. 把电话号码写下来以免忘了。 8. The doctor asked us to call him during the night except in case of necessity. 医生吩咐我们，除非必须，否则不要在夜里叫他。magazine 和 journal 有什么区别magazine .n A periodical containing a collection of articles, stories, pictures, or other features. 杂志：一种载有专论、小说、图片或其他内容的期刊。 journal .n 1.A personal record of occurrences, experiences, and reflections kept on a regular basis; a diary. 日志，日记：对于事件、经历及感想的有规律进行的私人记录；日志 2.An official record of daily proceedings, as of a legislative body. 议事录：关于（如立法机构的）日常议程的正式记录 3.Nautical A ships log. 【航海】 航海日志：船舶上的航海日志 4.Accounting 【会计学】 5.A daybook. 日记帐，流水帐 6.A book of original entry in a double-entry system, listing all transactions and indicating the accounts to which they belong. 分录簿：复式簿记系统中登载原始账目的账本，记录下所有的交易，并表示出它们所归的专项分类帐 7.A newspaper. 报纸 8.A periodical presenting articles on a particular subject: 期刊：刊登关于某特殊主题的文章的期刊.journal d:nl n. 杂志, 刊物, 日报; 航海日记 【会计】分类帐, 日记帐 日记, 日志, 笔记 the Journals(立法机关、委员会等的)议事录 【机】轴颈, 辊颈, 枢轴, 支耳 a medical journal 医学杂志 a monthly journal 月刊 magazine mzi:n n. 杂志; 期刊 (武器、弹药、炸药等的)仓库, 军火库 (连发枪上的)弹仓, 弹盒, 弹盘 (照象机的)底片夹盒; (软片, 胶卷)暗盒 资源地, 宝库 火炉中燃料室 (材料自动送进)料斗, 储料匣台, 架, 槽, (吹芯机)储砂筒, 卡片存储装置, 自动储存送料装置 edit a magazine 编辑杂志 weekly monthly, bi-monthly magazine 周刊月刊, 双月刊Journal 是指较专业性的杂志如学报。 Magazine 泛指一般杂志。will与 be going to do 和be to do和be about to do 和be doing有什么区别?在写句子时都可以用吗?1. will+动词原形，。 就是表示一般将来时。这个比较常用 2.be going to do 将会. 一般用于将来时态 例句与用法: 1. I am assuming that the present situation is going to continue. 我认为目前的情况将会继续下去. 2. Its going to cost 200 or as near as dammit. 这要花200英镑上下. 3. How did you find out that Burns was going to be promoted? 你是怎么知道伯恩斯将会得到提升的？ 4. You must be out of your mind if you think Im going to lend you 50! 你以为我会借给你50英镑, 你准是疯了! 5. Im just going to check in these books at the library. 我要去图书馆还这些书。 6. They are going to move to a new house next week. 下星期他们将迁入新居。 7. It looks as if it is going to rain. 看来要下雨了。 8. Are you going to America by boat or by plane? 你到美国是坐船还是坐飞机？ 3.be to do 表示安排、计划、决定、命令或注定要发生的事. 一般用于被动语态，to be done 也可以用于主动语态。都是表示将来时态 比如： Greater efforts to increase agricultural production must be made if food shortage is to be avoided. 为避免食物短缺，我们需要更加努力来提高农业生产。 The bridge is to be built next year. 大桥将在明年修建。 以下是主动语态的例句： He is to die. 他就要死了。 To live is to work. 活着就要工作。 比较： I am to be an engineer. 我就快要成为工程师了。（这个时间上快一点，而且比较有把握，比如已经考到证了。） 如果是： I am going to be an engineer. 意思就变成了： 我将成为工程师。（这个只是主观愿望。没有多少把握） 4.be about to do 表示即将，马上要做的事，。， 这个比其他的几个都要紧迫。 比如： I am about to leave. 我马上就要离开了。（刻不容缓，就是这一两分钟的事） 比较： I am going to leave. 我将要离开。（还指不定是什么时候） 5.be doing 主要用于现在进行时态，有时可以用来表达将来时 例句与用法: How are you doing with your new boss? 你跟你的新上司处得如何？ We are doing a pilot study to see if the new product will sell well. 我们正在为这种新产品做试销调查，看它的销路好不好。 According to these figures, our company is doing well. 从这些数字来看，我们的公司经营得不错。2. 英语语法问题!知道者快来!到底是be no use (to) do sth还是be no use dong sthbe no use doing sth是肯定的，绝对没错。 例如 It is no use watching too much TV. 看太多电视是没用的 这是固定搭配 所谓的接to do sth，是用在be used to do sth被用来做某事 It is no use trying to persuade him to have a holiday because he is a workaholic.(P53) 其中用了 Its no use doing sth. (做某事没用 / 只是白费力气)句型。在这个句型中， 动词-ing形式trying to persuade him to have a holiday是主语，it 是形式主语。这种动词-ing作主语，it 作形式主语的句型还有： 1. It is no good doing sth. 做某事不好 / 没用 / 不行 2. Its a waste of time / money doing sth. 做某事是白费时间 / 金钱 3. Its fun doing sth. 做某事很有趣1. It is no use _ me not to worry. a. you tell b. your telling c. for you to have told d. having told 为什么要选B？ 怎么分析 2. He is very busy _ his papers. He is far too busy _ callers. a. writing; to receive b. wrtiting; receiving 为什么选A？ far too busy 是太忙的意思，后面不跟doing 吗？it is no use + that从句 或者+doing(动名词形式) b 选项就是一个动名词形式 be busy doing sth 后面的空你理解错误了，应该理解为太忙而不能见访问者，所以应该考虑的是too.to do .结构（太。而不能。） 而不是考虑far too busy doing 结构He could have come to help us , but_.悬赏分：0 - 解决时间：2008-3-16 09:28He could have come to help us , but_. a.he didnt b. he hasnt c. he hadnt d. he cant 为什么选a不选b问题补充：如果后面写反义疑问句是不是用didnt he?提问者： chenjingjean - 试用期 一级 最佳答案这是一个虚拟语气中的常考句型，要记住。could have done的意思是“本可以做某事（而实际上没做）”。句型：Sb could have done sth, but + 一般过去时.的意思为：某人本可以做某事的，但（实际情况是）。由于后句讲述的是真实情况，故用一般过去时。 关于你的补充问题： He could have come to help us后的反意疑问句的tag理论上是didnt he，只是此句中He could have come to help us应该是一个确定的判断，一般不会用反意疑问句形式。 如果是猜测，则一定是didnt he. 请看下列例句： He could not have come to help you, did he? He must have come to help you, didnt he? He might have come to help you, didnt he? 祝周末愉快！情态动词的用法，can,may,must,need,could,dared情态动词有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等。 情态动词无人称和数的变化；不能单独使用，必须与其后的动词原形构成谓语 一、 can, could 1) 表示能力（体力、知识、技能）。 Can you lift this heavy box?（体力） Mary can speak three languages.（知识） Can you skate?（技能） 此时可用be able to代替。Can只有一般现在时和一般过去式；而be able to则有更多的时态。 Ill not be able to come this afternoon. 当表示“经过努力才得以做成功某事”时应用be able to，不能用Can。如： He was able to go to the party yesterday evening in spite of the heavy rain. 2) 表示请求和允许。 -Can I go now? - Yes, you can. / No, you cant. 此时可与may互换。在疑问句中还可用could, might代替，不是过去式，只是语气更委婉，不能用于肯定句和答语中。 - Could I come to see you tomorrow? - Yes, you can. ( No, Im afraid not. ) 3) 表示客观可能性（客观原因形成的能力）。 Theyve changed the timetable, so we can go by bus instead. This hall can hold 500 people at least. 4) 表示推测（惊讶、怀疑、不相信的态度），用于疑问句、否定句和感叹句中。 Can this be true? This cant be done by him. How can this be true? 二、 may, might 1) 表示请求和允许。might比 may语气更委婉，而不是过去式。否定回答时可用cant 或mustnt，表示“不可以，禁止”。 -Might/ May I smoke in this room? - No, you mustnt. - May/Might I take this book out of the room? - Yes, you can. (No, you cant / mustnt. ) 用May I.？征徇对方许可时比较正式和客气，而用Can I.？在口语中更常见。 2）用于祈使句，表示祝愿。 May you succeed! 3) 表示推测、可能性（不用于疑问句）。 might不是过去式，它所表示的可能性比may小。 1He may /might be very busy now. 2Your mother may /might not know the truth. 三、 must, have to 1) 表示必须、必要。 You must come in time. 在回答引出的问句时，如果是否定的，不能用mustnt（禁止，不准），而用neednt, dont have to（不必）. - Must we hand in our exercise books today? - Yes, you must. - No, you dont have to / you neednt. 2) must是说话人的主观看法， 而have to则强调客观需要。Must只有一般现在时， have to 有更多的时态形式。 1 he play isnt interesting, I really must go now. 2 I had to work when I was your age. 3) 表示推测、可能性（只用于肯定的陈述句） 1 Youre Toms good friend, so you must know what he likes best. 2 Your mother must be waiting for you now. 四、 dare, need 1) dare作情态动词用时, 常用于疑问句、否定句和条件从句中, 过去式形式为dared。 1 How dare you say Im unfair? 2 He darent speak English before such a crowd, dare he? 3 If we dared not go there that day， we couldnt get the beautiful flowers. 2) need 作情态动词用时, 常用于疑问句、否定句。在肯定句中一般用must, have to, ought to, should代替。 1You neednt come so early. 2. - Need I finish the work today? - Yes, you must. / No, you neednt. 3) dare和 need作实义动词用时， 有人称、时态和数的变化。在肯定句中，dare后面常接带to的不定式。在疑问句和否定句中，dare后面可接带to或不带to的不定式。而need后面只能接带to的不定式。 1. I dare to swim across this river. 2. He doesnt dare (to) answer. 3. He needs to finish his homework today. 五、 shall, should 1) shall 用于第一人称，征求对方的意见。 What shall we do this evening? 2) shall 用于第二、三人称，表示说话人给对方的命令、警告、允诺或威胁。 1. You shall fail if you dont work hard.(警告) 2. He shall have the book when I finish it.(允诺) 3. He shall be punished.(威胁) 六、 will, would 1) 表示请求、建议等，would更委婉。 Will / Would you pass me the ball, please? 2) 表示意志、愿望和决心。 1. I will never do that again. 2. They asked him if he would go abroad. 3) would表示过去反复发生的动作或某种倾向。would表示过去习惯时比used to正式，且没有“现已无此习惯”的含义。 1. During the vacation, he would visit me every other day. 2. The wound would not heal. 4) 表示估计和猜想。 It would be about ten oclock when she left home. 七、 should, ought to 1) should, ought to表示“应该”，ought to表示义务或责任，比should语气重。 1. I should help her because she is in trouble. 2. You ought to take care of the baby. 2) 表示劝告、建议和命令。should, ought to可通用，但在疑问句中常用should。 1. You should / ought to go to class right away. 2. Should I open the window? 3) 表示推测 should , ought to (客观推测), must(主观推测)。 1.He must be home by now. (断定他已到家) 2.He ought to/should be home by now.(不太肯定) 3. This is where the oil must be.(直爽) 4. This is where the oil ought to/should be.(含蓄) 八、 情态动词+不定式完成式（have done） 1) can / could + have done在肯定句中表示“本来可以做而实际上能做某事”，是虚拟语气；在疑问句或否定句中表示对过去行为的怀疑或不肯定, 表示推测。 1. You could have done better, but you didnt try your best. （虚拟语气） 2. He cant have been to that town.（推测） 3. Can he have got the book?（推测） 2) may / might +不定式完成式（have done） 表示对过去行为的推测。不能用于疑问句中，没有虚拟语气的用法。Might所表示的可能性比may小。 1. He may not have finished the work . 2. If we had taken the other road, we might have arrived earlier. 3）must +不定式完成式（have done） 用于肯定句中，表示对过去行为的推测。意为“一定、想必”。其疑问、否定形式用can，cant代替。参看1) can / could + have done表示推测。 1. You must have seen the film Titanic. 2. He must have been to Shanghai. 4）should +不定式完成式（have done） 用于肯定句中，表示对过去行为的推测。 He should have finished the work by now。 表示“本应该做而实际上没有做某事”，其否定式表示某种行为本不该发生却发生了。可以与ought to +不定式完成式（have done）互换。 1. You ought to / should have helped him. (but you didnt.) 2. She shouldnt have taken away my measuring tape, for I wanted to use it. 5) neednt +不定式完成式（have done） 表示“本来不必做而实际上做了某事”。 You neednt have watered the flowers, for it is going to rain. 6) will +不定式完成式（have done） 主要用于第二、三人称，表示对已完成的动作或事态的推测。He will have arrived by now.It is not the tools a scientist uses but how he uses the tools that makes him a scientist.It is not the tools a scientist uses but how he uses the tools that makes him a scientist. 这句话什么意思,that引导的是什么从句.It is.that.的强调句 Not the tools a scientist uses but how he uses the tools makes him a scientist. Not the tools a scientist uses but how he uses the tools 为主语 科学家之所以成为一个科学家，不是由于他所使用的工具而是由于他是如何使用这些工具used to 和be used to的区别一、在英国英语中传统上把used to看作是情态动词，因此，它的疑问式应当是：Used 主语to sth？否定式应当是used not to或use（d）nt to。但是，在美国英语中，人们把used to看作是实义动词，因此，它的疑问式是：Did 主语use to do sth？否定式是：主语didnt use由于受到美国英语的影响，甚至在英国英语中，人们也很少使用“Used主语to”这种疑问式，而使用“Did 主语use”这一疑问式。例如： Did they use to play football？他们过去踢足球吗？ Did you use to smoke？你过去吸烟吗？ Did you use to take long walks in the countryside？你过去在农村经常进行长距离的散步吗？ 二、在带有used to的陈述句后面，附加疑问句中一般要使用功能词did。但是，在附加疑问句中也可以用used。例如： He used to smoke，didnt he？ They usednt to like opera，did they？ They didnt use to like opera，did they？ They used not to like opera，did they？ You used to live in Wuhan，usednt you？ You used to like wine，use（d）nt you？ 三、used to的否定形式的一般问句常有以下两种。例如： Didnt you use to live near me？ Usent you to live near me？你过去不住在我附近吗？ 四、used to指的是过去的习惯性动作，目的在于与现在形成对照，如：I used to work hard是说“我过去常常努力工作。”暗含的意义是：我现在不努力工作了。在表示过去的习惯性这一点上，与would的意义相同（只不过used to既可用于表示过去的习惯动作，又可用于表示过去的状态。would只能用于表示过去习惯性的动作）。从形态上看used to是个情态动词，其中的to是不定式符号，后面跟动词原形。例如： When I was a child，I would get up early People used to（不用would）believe the earth was flat过去人们认为地球是平的。 I used to like swimming When I was a child，I used to（不用would）like swimming 我哥哥过去是解放军，现在是教师。 误：My elder brother would be a PLA manHe is now a teacher 正：My elder brother used to be a PLA man He is now a teacher 五、be（get，become）used to结构在意义上相当于accustomed to“习惯于”，从形态上看，used是个分词型形容词，to是介词，因此后面只能跟名词、代词或动名词。例如： They got used to living in the countryside他们已习惯于住在农村。 Ive got used to being a vegetarian我已经习惯吃素食。 He is used to hard work他习惯于艰苦工作。 六、be used to表示“习惯于某事”的状态，而get used to则表示由“不习惯”到“习惯于”这一动态的过程，意思是：“（变得）习惯于”；“开始习惯于”。试比较： He was used to the cold weather after he lived there for two years在那里住两年后，他已习惯了寒冷的天气。 I think it is a bit difficult for you to get used to the humid weather here我想，让你习惯于这里潮湿而炎热的天气有点困难。 Youll soon get used to living in the country很快你就会习惯于住在乡下了。 七、有时be used to是动词use的被动语态，在这种结构里，to是不定式符号。例如： A metal bar was used to force the door open用金属棒把门撬开。 The threshing ground was used to hold a mass meeting打谷场曾用于举行群众大会。 八、be used to与be accustomed to的区别：前者一般用于指自然而然地成为习惯，后者常常用于指通过努力而成为习惯。试比较： I am used to teaching English我对教英语已习惯了。 Mrs Smith was not accustomed to leaving home during the winter史密斯夫人不习惯冬天出门。 I am accustomed to taking coffee我习惯了喝咖啡。回答者：nc3722 - 试用期 一级 11-23 11:10提问者对于答案的评价：you are the best !thank you!评价已经被关闭目前有 1 个人评价窗体顶端好100% （1）不好0% （0）窗体底端其他回答共 3 条used to 是“过去常常做什么”后接动词原形 be used to 是“习惯做什么”后接名词和动名词（ing)回答者：yalinge - 助理 二级 11-23 11:05才实际的口语中他们大量用到： used to 表示的是 过去的一种状态，比如hey man, I used to do this job,is it funny huh?接原型。 Be/get used to 翻译成习惯于，接ing形式，比如，I am used to not having dinner when my wife fights with me 我们常常容易记不住他们的区别，告诉你你一个方法就是：used to 翻译成过去常常的四个中文比 be used to 的习惯于 长，换句话说就是长的中文和短的英文在一起