专四必备语法.doc

专四必备语法专四必备语法一、时态、语态 时态、语态需要掌握的要点：1.表达将来时的形式：(1)在时间、条件、让步从句中，一般现在时代替将来时，但要注意区别从句的类型，如：Ill tell him when you will ring again. 我告诉他你什么时候再来电话。(宾语从句)比较：Ill tell him when you ring again.你再打电话时我告诉他。(状语从句)(2)在make sure, make certain, see (to it) 后的that从句中，谓语动词用一般现在时代替将来时，如：See to it that you include in the paper whatever questions they didnt know the answer to last time.(include 不能用will include或其他形式)2.完成时是时态测试的重点，注意与完成时连用的句型和时间状语：(1)by/between/up to/till +过去时间、since、by the time/when +表示过去发生情况的从句，主句用过去完成时。如：We had just had our breakfast when an old man came to the door.Between 1897 and 1919 at least 29 motion pictures in which artificial beings were portrayed had been produced.(表示1919年时已发生的情况)(2)by +将来时间、by the time/ when +谓语动词是一般现在时的从句，主句用将来完成时。如：By the time you arrive in London, we will have stayed in Europe for two weeks.I hope her health will have improved greatly by the time we come back next year.(3)by now、since +过去时间、in/during/for/over/the past/last few(或具体数字)years/days/months，主句用现在完成时,如：The changes that had taken place in air travel during the last sixty years would have seemed completely impossible to even the most brilliant scientists at the turn of the 19th century.但在it is +具体时间since/before这一句型中，主句更多的时候不用完成时。It is four years since John left school.(4)在It is the +序数词/形容词最高级+that的定语从句中，谓语动词常用现在完成时。如： It isnt the first time that I have found myself in an embarrassing situation.(5)在no soonerthan, hardly/scarcelywhen句型中，主句常用过去完成时。3.完成进行时指动作在完成时的基础上还要继续下去。如： The company has been promising a rise in salary for ages, but nothing has happened.时态、语态答题思路：(1)先根据选项的区别点确定考题要点为时态，然后回到题句中寻找给出的或暗示的时间状语，缩小选择范围，进而选出正确答案；(2)根据谓语动词与句子主语或非谓语动词与其逻辑主语的关系，确定句子是主动语态还是被动语态。二、不定式1.不定式做主语(1)引导逻辑主语的介词：不定式的逻辑主语一般由介词for引导,但下列表示人的性格行为特征的形容词做表语时, 不定式的逻辑主语则由of引导：absurd, bold, brave, courageous, careful, careless, clever, wise, foolish, silly, stupid, good, nice, kind, thoughtful, considerate, greedy, generous, honest, modest, polite, rude, cruel, selfish, lazy, wicked, wrong。如：Experts say walking is one of the best ways for a person to stay healthy.Its clever of you to have invented such a device.(2)不定式做主语补足语：掌握常用不定式做主语补足语的句型。注意不定式表示的动作发生的时间，并采用相应形式。如：be said / reported / thought / believed / known / supposed + to do sth.2.不定式做宾语掌握要求接不定式做宾语的动词：afford, arrange, attempt, claim, desire, determine, expect, fail, guarantee, endeavor, intend, pledge, pretend, resolve, request, swear, tend, venture。如：Even though the children pretended to be asleep, the nurses were not deceived when they came into the room.3.不定式做定语(1)被修饰的名词前有序数词、形容词最高级或next, last, only, not a, the, very等限定词时，该名词用不定式做定语。如：the first woman to set foot on the moon 第一个登上月球的女性(2)如果其动词要求不定式做宾语，相应的名词一般用不定式做定语。如：tendency to dotend to do, decision to dodecide to do This book is an attempt to help you use English and recognize how it is used.(3)如果其形容词形式要求接不定式做补语，相应的名词一般用不定式做定语。如：ambition to do “干的雄心”be ambitious to do“有雄心干”curiosity to do “对的好奇心”be curious to do“对好奇”ability to do“做的能力”able to do“有能力做”According to Darwin, random changes that enhance a species ability to survive are naturally selected and passed on to succeeding generation.(4)表示方式、原因、时间、机会、权利等名词用不定式做定语，这些名词包括：way, method, reason, time, place, chance, occasion, opportunity, evidence, power, right, movement, drive (运动)，effort等。如：I worked so late in the office last night that I hardly had time to catch the last bus.We appreciate your efforts to bring about a comprehensive solution to the existing problem.(5)不定代词something, nothing, little, much, a lot习惯上用不定式做定语。如：Though we have made great progress, there is still much to be improved.4.不定式做状语不定式做状语主要表示目的、程度、结果、方式。(1)in order to(do), so as to(do)结构引导目的状语，so as to不能置于句首。如：(2)soas to, suchas to, enoughto, tooto结构做程度状语。如：The solution works only for couples who are self-employed, dont have small children and get along well enough to spend most of their time together.The vocabulary and grammatical differences between British and American English are so trivial and few as hardly to be noticed.(3)不定式做结果状语只能出现在句子的末尾，表示不愉快的结果，有时用only加强语气。常见的不定式动词有find, hear, see, be told, form, give, make, produce等。如：Greatly agitated, I rushed to the apartment and tried the door, only to find it locked.(4)not/never too to, too not to, but/only tooto, too ready/eager/apt/inclined to 表示肯定意义。如：I am only too pleased to hear from you further. 能再听到你的消息，我太高兴了。三、动名词1.必须接动名词做宾语的动词牢记下列要求接动名词做宾语的动词：acknowledge, advocate, anticipate, appreciate, avoid, admit, confess, consider, delay, deny, enjoy, escape, excuse, fancy, favor, finish, forgive, imagine, involve, justify, mention, pardon, practice, postpone, recall，recollect，risk, resist, suggest, tolerate。如：I appreciate having been given the opportunity to study abroad two years ago.2.动名词做介词短语考生尤其要识别下列短语中的to是介词，不是不定式符号：object to, resort to, react to, contribute to, look forward to, be accustomed to, be committed to, be exposed to, be subjected to, be devoted to, be dedicated to, be opposed to, be reconciled to, be contrary to, be (get) used to, come close to, get down to, give oneself up to, preferto, see to, set to, take to, in addition to, with regard to, with a view to, on the way to。如：四、分词分词起形容词和副词的作用，在句中做定语或状语。在概念上应清楚： 现在分词表示主动，表示动作在进行。 过去分词表示被动，表示动作结束了的状态或结果。1.分词做定语，弄清现在分词与过去分词的区别分词短语做定语相当于省略了的定语从句，考生应掌握：(1)现在分词与被修饰词之间具有主动意义。如：Its easy to blame the decline of conversation on the pace of modern life and on the vague changes taking place in our ever-increasing world.(相当于the changes which take place.)There was a very interesting remark in a book by an Englishman that I read recently giving what he thought was a reason for this American characteristic.(相当于which gave.)How many of us attending, say, a meeting that is irrelevant to us would be interested in the discussion?(相当于How many of us who will attend.)(2)过去分词与被修饰词之间具有被动意义。如：Good news was sometimes released prematurely, with the British recapture of the port announced half a day before the defenders actually surrendered. (相当于recapture of the port which had been announced)Just as the value of a telephone network increases with each new phone added to the system, so does the value of a computer system increase with each program that turns out. (相当于each new phone which is added to)The author gave a detailed description based on his personal observation of nature.(相当于description which was based on)(3)下列不及物动词也以过去分词形式做定语或表语，但不具有被动意义：deceased, departed, elapsed, faded, fallen, gone, grown-up, retired, returned, risen, set, vanished, much-travelled, newly arrived, recently come。如：an escaped prisoner一个逃犯a retired worker一位退休工人a faded curtain一个褪了色的窗帘a newly arrived student一个新来的学生2.分词做状语，注意区分分词的一般式与完成式(1)表示时间，多置于句首，注意如果分词表示的动作的时间先于谓语动词，要用完成式。如：Having completed one task, we started on another one. (complete先于start之前发生)(2)表示原因，置于句首句尾均可，根据情况有时要用完成式，有时用一般式。如：He wasnt asked to take on the chairmanship of the society, being considered insufficiently popular with all members.There seemed little hope that the explorer, having been deserted in the tropical forest, would find his way through it.(3)表示伴随、方式，置于句尾，用分词的一般式。如：Helen borrowed my dictionary the other day saying that she would return it soon.Anna was reading a piece of science fiction, completely lostto the outside world.(4)表示结果，置于句尾，用分词的一般式。如：The city found itself in a crisis situation last summer when the air conditioning on dozens of the new buses broke down, them unusable.(5)表示补充说明(同位)，置于句尾，用分词的一般式。如：The article opens and closes with descriptions of two news reports, each making one major point in contrast with the other.Ford tried dividing the labor, each worker assigned a separate task.3.分词的独立主格结构分词的逻辑主语一般为句子的主语，否则分词短语要有自己的逻辑主语，称为分词独立主格结构。分词独立主格结构只是句子的一个部分。如：All flights having been canceled because of the snowstorm, we decided to take the train.Darkness setting in, the young couple lingered on merrymaking.五、非谓语动词的其他考点1.接不定式或动名词做宾语都可以，但在意思上有区别的动词的用法mean to do想要(做某事) propose to do 打算(做某事)mean doing意味(做某事) propose doing建议(做某事)forget to do忘记(要做的事) remember to do记得(要做某事)forget doing忘记(已做的事) remember doing记得(已做过的事)go on to do继而(做另一件事) stop to do停下来去做另一件事go on doing继续(做原来的事) stop doing停止正在做的事regret to do(对将要做的事)遗憾 regret doing(对已做过的事)后悔2.不定式的习惯用法句型：cannot help but do cannot but docannot choose but do can do nothing but dohave no choice/alternative but to do上述句型的意思接近，即“不得不做”、“不禁做”、“不由自主地做”、“不能不做”、“只能做”。如：Nobody can help but be fascinated by the world into which he is taken by the science fiction. When I consider how talented he is as a painter, I cannot help but believe that the public will appreciate his gift.3.动名词的习惯用法句型：be busy/active doing sth. have difficulty/trouble/problem doing sth.Its no good/use/picnic doing sth. have a good/great/wonderful time doing sth.spend/waste time doing sth. There is no point/sense/harm/ use doing sth.cannot help doing sth. There is no doing sth.I know it isnt important but I cant help thinking about it.Alice was having trouble controlling the children because there were so many of them.There is no use crying over spilt milk.4.there be 非谓语动词的用法(1)做宾语时取决于谓语动词的持续要求。如：The students expected there to be more reviewing classes before the final exams.(expect要求接不定式做宾语)(2)做目的状语或程度状语时用for there to be，做其他状语用there being。如：For there to be successful communication, there must be attentiveness and involvement in the discussion itself by all present.(for there to be在句中做目的状语)It isnt cold enough for there to be a frost tonight, so I can leave Jims car out quite safely.(for there to be在句中做程度状语)There being no further questions, well stop here today. (there being做原因状语)(3)引导主语用for there to be。如：It is unusual for there to be no late comers today.(4)做除for外的介词宾语，用there being。如：He would always ignore the fact of there being such a contradiction in his inner thought.六、虚拟语气1.主从句谓语动词的时态(1)掌握主从句谓语动词的规范搭配:主句从句与现在事实相反would/情态动词过去式+dowere (不分人称)/did与过去事实相反would/情态动词过去式+have donehad done与将来事实相反would/情态动词过去式+doshould do / were to do如：If the doctor had been available, the child could not have died.There is a real possibility that these animals could be frightened, should there be a sudden loud noise.(2)区分主从句表示的不同时间概念：主从句谓语动词所指时间不同，这叫做错综时间条件句，动词形式应根据实际情况来调整。如：Had it not been for the timely investment from the general public, our company would not be so thriving as it is.(主句与现在事实相反，从句与过去事实相反)Had Paul received six more votes in the last election, he would be our chairman now.(主句与现在事实相反，从句与过去事实相反)(3)识别事实和假设混合句：Your math instructor would have been happy to give you a make-up examination had you gone and explained that your parents were ill at the time.(句子前半部分为假设情况，而“父母病了”是事实)I would have gone to visit him in the hospital had it been at all possible, but I was fully occupied the whole of last week.(前半部分为假设，后半部分是事实)2.名词性从句的虚拟形式名词性从句是指宾语从句、主语从句、表语从句和同位语从句。从句的谓语动词需用(should+)动词原形表示虚拟。考生应熟悉：(1)下列动词做谓语时，that宾语从句中的动词用虚拟形式：desire, advise, recommend, command, direct, order, ask, demand, request, require insist, maintain, move, propose, prefer, urge, vote。如：In the past men generally preferred that their wives work in the home.I move that he be discharged for his serious mistake.(2)下列形容词和分词做表语或补语时，that主语从句中动词用虚拟形式：advisable, desirable, insistent, preferable, urgent, appropriate, compulsory, crucial, essential, imperative, important, necessary, obligatory, possible, probable, proper, vital, advised, arranged, commanded, demanded, desired, ordered, proposed, recommended, requested, required, suggested。如：The board deem it urgent that these files should be printed right away.It is essential that all these figures be checked twice.(3)下列名词接同位语从句或表语从句时，从句中动词用虚拟形式：insistence, preference, recommendation, suggestion, proposal, motion, desire, requirement, request, order, necessity, importance, regulation, rule, resolution, understanding。如：John Wagners most enduring contribution to the study of Afro-American poetry is his insistence that it be analyzed in a religious, as well as worldly, frame of reference.They keep telling us it is of utmost importance that our representative be sent to the conference on schedule.3.含蓄虚拟条件句的谓语动词形式含蓄虚拟语气是指假设条件不通过if从句表达，而是暗含在其他结构中。考生应熟悉：(1)连词but, but that, or, or else；副词otherwise, unfortunately等表示转折假设。如：A safety analysis would have identified the target as a potential danger. Unfortunately, it was never done.Victor obviously doesnt know whats happened; otherwise he wouldnt have made such a stupid remark.(2)介词短语暗含假设条件，常用的有：without, but for, under more favorable conditions等。如：But for the English examination I would have gone to the concert last Sunday.(3)intended/meant/hoped/wished/planned或was/were +不定式完成式或had intended/meant/planned/hoped/wished+不定式一般式暗示虚拟语气。如：I intended to have called on you, but I was busy at that time.(4)情态动词完成式暗示虚拟语气。如：I should have called to make an airline reservation, but I didnt.4.常用虚拟形式的句型(1)从句中动词用过去式或过去完成式表示虚拟的句型：would rather would as soon as though supposehad rather would sooner as if supposingIf only It is (high) time that(从句中动词只用过去式)如：His wife would rather they didnt talk about the matter any more.Id rather you went by train, because I cant bear the idea of your being in an airplane in such bad weather.If I were in a movie, then it would be about time that I buried my head in my hands for a cry.My father always talks as though he were addressing a public meeting.(2)If it were not for (与现在事实相反)If it had not been for (与过去事实相反) 相当于but for。如：If it had not been for his help (= but for his help), we would not have succeeded.(3)If only谓语动词视情况选用适当的形式。如：If only the committee would approve the regulations and put them into effect as soon as possible.(4)lest/for fear that/in case 从句谓语用(should+)动词原形。如：The mad man was put in the soft-padded cell lest he injure himself.(5)whetheror有时谓语用be的原形，引导让步虚拟从句，这种用法经常采用倒装结构。如：Church as we use the word refers to all religious institutions, be they Christian, Islamic, Buddhist, Jewish, and so on.The business of each day, be it selling goods or shipping them, went quite smoothly.七、情态动词注意情态动词完成式的用法有两方面的含义：1.表示已经发生的情况(1)must have +过去分词，表示对已发生情况的肯定推测，译为“(昨天)一定”。如：My pain must have been apparent the moment I walked into the room, for the first man I met asked sympathetically: “Ar