1、专四必备语法(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.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
2、school(一般过去式).(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 ha
3、ppened. 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：Experts say walking is one of the best ways for a person to stay healthy.、It is silly of you to be cheated by himIts clever of you to have invented such a device.Its time for you to get up.3.不定式做定语做后置定语。如：
4、the first woman to set foot on the moon 第一个登上月球的女性This book is an attempt to help you use English and recognize how it is used.According to Darwin, random changes that enhance a species ability to survive are naturally selected and passed on to succeeding generation.(5)不定代词 something, nothing, littl
5、e, 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.I want something to eat.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。so as to 不能置于句首。如：The solution works only for couples who are self-employed, dont have small children and get along well enough to spend most of th
6、eir time together.The vocabulary and grammatical differences between British and American English are so trivial and few as hardly to be noticed.only to 表示意想不到的结果， Greatly agitated, I rushed to the apartment and tried the door, only to find it locked.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,
7、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 t
8、o 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, co
9、me 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 eas
10、y to blame the decline of conversation on the pace of modern life and on the vague changes taking place in our ever-increasing world.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 gav
11、e.)How many of us attending 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 sur
12、rendered. (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,Just with the value of a telephone network increasing withThe author gave a detailed description based on his personal observation of nature.(相当于des
13、cription which was based on)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)3.分词的独立主格结构分词的逻辑主语一般为句子的主
14、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.Weather permitting , we will go on a picnic.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(
15、 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)regret to do(对将要做的事 )遗憾 regret doing(对已做过的事 )后悔三、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 bu
16、t 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.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
17、 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 le
18、ave 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 contra
19、diction 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:从句 主句与现在事实相反 were (不分人称)/did would/情态动词过去式+do与过去事实相反 had done would/情态动词过去式+have done与将来事实相反 should do / were to do would/情态动词过去式+do如：If the doctor had been available, the child could not have died.(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
20、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 wou
21、ld 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
22、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
23、 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, demande
24、d, 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, mo
25、tion, 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
26、 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. Unfor
27、tunately, 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/w
28、ished/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 a
29、s 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
30、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.(3)If only(要是。 。 。就好了) 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
31、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. 3.几个情态动词常考的句型(1)may/might (just) as well“不妨，最好” ，与 had better 相近。如：Since the flight was cancelled, you might as well go by train.(2)cannot/canttoo “越越好，怎么也不过分”。注意这个句型的变体cannotover。如：You cannot be too careful wh
32、en you drive a car.(4)should 除了“应该”一层意思外，大纲还规定要掌握其“竟然” 的意思。如：I didnt expect that he should have behaved like that.3.最高级形式应注意的问题比较级形式表示最高级意义时，比较对象的范围应用：any other +单数名词the other +复数名词the othersanyone/anything else上述词是用来将比较级结构转变成最高级意义的关键词语，切不可遗漏，否则会造成逻辑混乱的错误。(1)not so muchas与其说不如说The chief reason for t
33、he population growth isnt so much a rise in birth rates as a fall in death rates as a result of improvements in medical care.(2)no/（not any） morethan两者一样都不The heart is no more intelligent than the stomach, for they are both controlled by the brain.There is no reason they should limit how much vitami
34、n you take, any more than they can limit how much water you drink.(3)no /not any lessthan两者一样都She is no less beautiful than her sister.(4)just asso.正如 ，也(用倒装结构)Just as the soil is a part of the earth, so is the atmosphere.九、平行结构1.注意比较结构中相比较的内容在语法形式上是否相同。如：It is better to die on ones feet than to liv
35、e on ones knees.Despite the temporary difficulties, the manager prefers increasing the output to decreasing it.2.其他具有并列或比较意义的短语。(1)rather than, let alone 虽不是并列连词，但在结构上连接两个语法形式相同的成分。如：We are taught that a business letter should be written in a formal style rather than in a personal style.For the new
36、country to survive, let alone for its people to enjoy prosperity, new economic policies will be required.(2)如果平行的两个成分在形式上是介词短语，而且介词相同，一般说来第二个介词不要省略。如：At times, more care goes into the composition of newspaper and magazine advertisements than into the writing of the features and editorials.十、代词2.that
37、 的指代作用that 指代不可数名词和单数可数名词( 如是复数，用 those)，后面通常跟有修饰语，如出现在比较结构中的that of。如：Conversation calls for a willingness to alternate the role of speaker with that of listener, and it calls for occasional “digestive pauses” by both.No bread eaten by man is so sweet as that earned by his own labor.3.one 的指代作用one
38、指代不确指的单数可数名词，复数为 ones。the one 指代确指的单数可数名词。如：A good writer is one who can express the commonplace in an uncommon way.十一、主谓一致问题1.主语与谓语之间有定语从句或其他结构修饰，所以距离较远，考生易误认主语。如：The amount of pressure which the materials are subject to affects the quality of the products.2.关系代词做主语的定语从句中，谓语的数要与先行词一致。如：Despite much
39、 research, there are still certain elements in the life cycle of the insect that are not fully understood.There are many valuable services which the public are willing to pay for, but which do not bring a return in money to the community.3.动名词短语、不定式短语、名词性从句做主语，谓语用单数。如：Buying clothes is often a time-
40、consuming job because those clothes that a person likes are rarely the ones that fit him or her.To understand the situation completely requires more thought than has been given thus far.4.主语带有(together/along)with, such as, as well as, accompanied by, including, rather than 等附加成分, 谓语的数不受附加成分的影响。如：The
41、 president of the college, together with the deans, is planning a conference for the purpose of laying down certain regulations.5.表示时间、距离、金额、重量、面积、体积、容积等度量的名词短语做主语时，谓语用单数。6.某些固定结构中谓语的数：a great many + 可数名词复数 谓语用复数many a + 可数名词单数 谓语用单数a number of +可数名词复数 谓语用复数the number of +可数名词复数 谓语用单数the majority of
42、 +可数名词复数 谓语用复数each/every +可数名词单数 谓语用单数neither/either of +可数名词复数 谓语用单数more than one +可数名词单数 谓语用单数one and a half +可数名词复数 谓语用单数the greater part of / a large proportion of / 50% of / one third of / plenty of / the rest of 谓语的数与 of 后面的名词一致十二、倒装结构2.以 only 修饰状语开头的句子，句子的主谓要部分倒装Only you(主语) can do this。Only
43、when you have obtained sufficient data can you come to a sound conclusion.3.以下列副词或短语开头的句子，句子的主谓要部分倒装often, so, well, to such a degree, to such an extent, to such extremes, to such a point， many a time。 如：So involved with their computers do the children become that leaders at summer computer camps of
44、ten have to force them to break for sports and games.4.以下列副词开头的句子，句子的主谓要全部倒装(1)出于修辞需要，表示方向的副词：out, down, in, up, away, on。如：Here comes the teacher. Here you are.Down jumped the burglar from the tenth floor when he heard someone shouted at him.(2)出于习惯用法：here, there, now, thus, hence, then。如：Now is yo
45、ur turn. There goes the bell.5.让步从句的倒装(1)as 引导让步状语从句，必须采用倒装结构，但不是主谓倒装，而是将被强调的内容置于句首。如：Much as I have traveled, I have never seen anyone to equal her, in thoroughness, whatever the job.(2)出现在句型 be+主语+ 其他 , come what may 中。如：Our civilization has accumulated an incredible amount of knowledgebe it scien
46、tific or artistic.The business of each day, be it selling goods or shipping them, went quite smoothly.Come what may, Ill be on your side.6.比较从句的倒装as, than 引导的比较从句中，如果主语是名词短语且较长，经常采用倒装结构(不倒装也可以) 。注意：这种结构主语一般为名词，如果是代词则不倒装。如：Hydrogen burns much more cleanly than do other fuels and is easy to produce.Re
47、ading is to the mind as is exercise to the body.十三、复合句形容词性(定语) 从句1.尤其要注意 whose 的用法whose 在从句中做定语，修饰名词。所以，如果关系代词后面紧接的是名词，且关系代词又不在从句中做主语或宾语，那么，这个关系代词就应该是 whose。如：2.介词 + which 的用法如果从句中主宾成分齐全，考生便可考虑关系代词是否在从句中做状语，而状语通常用介词短语充当，于是可以得知，关系代词前面应有介词，再分析所给的选项，根据与名词的搭配作出正确选择。如：We are not conscious of the extent t
48、o which work provides the psychological satisfaction that can make the difference between a full and an empty life.3.as 与 which 用作关系代词的区别(1)as 与 the same, such, so, as 等关联使用。如：As the forest goes, so goes its animal life.(2)as 和 which 都可以引导非限定性定语从句，但 as 在句中的位置比较灵活，可出现在句首、句中、句末，而 which 只能出现在句末，尤其是当先行词
49、是整个句子时。如：As is true in all institutions, juries are capable of making mistakes.As is generally accepted, economic growth is determined by the smooth development of production.常见的这类结构有：as has been said before, as has been mentioned above, as can be imagined, as is known to all, as has been announced, as can be seen from these figures, as might/c
