限制性定语从句as

　　近几年高考试卷中有关as一词的题目出现过很多次，其中as或是最佳选项，或是干扰项，或是题干中的关键信息点，涉及到as作为连词、介词、关系代词、副词以及习语等各种用法。as的用法有哪些呢?本文是小编整理as的用法的资料，仅供参考。

　　限制性定语从句as 1

　　as的用法

　　(一)、as作连词的用法:

　　1.作“在…期间，当…的时候”引导时间状语从句.注意与when、 while的用法区别。

　　①下列情形时,只用as, 而不用when或while。

　　1)用于表示同一个人的两种动作交替进行,指一边----一边. 如:

　　The girl sings as she goes to school.

　　He looked behind occasionally as he went forward in the forest.

　　2)表示两个同步发生的动作或行为,意思是随着…的发展.如:

　　As time went on / by, she became more and more beautiful.

　　As children get older, they become more and more interested in everything.

　　3)表示两个短暂行为或事情几乎同时发生.如:I watched her as she read the book. I thought of it just as you opened your mouth.

　　Just as the flying worm hit her face, she gave a loud cry.

　　4)接名词表示某一个年龄段时.如:

　　As a young man, he was active in sports.

　　As a little boy (When he was a little boy) he began to learn to play the piano.

　　②when作"当的时候"解,可以指较短的(一点)时间,也可指一段时间。

　　如:When I was at college, I could speak several foreign languages.

　　When the clock struck twelve, I had slept for 2 hours.

　　I was wandering through the street when I caught sight of a tailor’s shop有意料之外的意思

　　③ while常表示一段较长的时间或一个过程,强调主句谓语动词与从句谓语动词同时

　　如:Work while you work. Play while you play.

　　Strike while the iron is hot趁着

　　2. As =Since 作"既然"、"由于"解,常用来表示已为人们所知或显而易见的原因或理由。如: As he’s been ill for ages, I will help him.

　　As / Since you're not feeling well, you may stay at home.

　　As he wasn't ready, we went without him.

　　3. As =in the way that作"像"、"按照的方式"解,引导方式状语从句。如: Do as I told you. Remember, you must do everything as I do. Take the medicine asdirected. Maglev trains don’t make much noise, as planes do. When at Rome，do asRomans do.入乡随俗 As in your country，we grow wheat in the north and rice in the South.

　　4. 用于as--- as或not / so/ as ---- as中,前一个as是副词,后一个as是连词,引导比较状语从句。如:They helped the old as much as possible.

　　I don't speak English so/ as well as she does.

　　5. 表示虽然,尽管等,引导让步状语从句,常用倒装语序,模式为: adj. /adv. / n.+as+主语+谓语+主句。如: Tired as they were, they walked on. Child as he is ，he knows a lot.Fast as he ran，he didn't catch the bus.Much as I respect him, I won’t do as suggests. Try as you may, you might fail again Try as he might，Tom could not get out of the difficulties.

　　6. 表示也------一样。 She is a doctor, as was her husband.

　　(二)、 as作关系代词,引导定语从句,表示正如,这一点.如:

　　He is very careful, as we all know. As is well-known, Taiwan belongs to China.

　　另外,当先行词被the same, such, so等词修饰时,常用as来引导定语从句。如:

　　Such a clever girl as she can learn anything quickly.

　　He wished to be such a man as Lei Feng was.

　　I was reading the same book as he bought yesterday. This book is not such asI expect

　　Note: He took the police back to the same place where he witnessed the robbery

　　(三)、as作介词的用法.

　　1.表示好像。如:He dressed as a policeman. They got united as one man.

　　2.表示作为当作。如：I found a job as a guide.

　　3.当某人是某身份时。如：As a child , she was sent to abroad.

　　4.as引导的介词短语大多用作状语,as译为"作为";少数情况可引起宾语补足语。如: Asa Party member, I'll take the lead in everything. (状语) She works as a model. (状语) She has me as one of her best friends.(引起宾语补足语)

　　(四)、作副词的用法

　　1 表示与------等同。如：This dress is twice as expensive as that one.

　　2 像，如等。As before, he remained unmoved. He doesn't speak English as/so fluently as you.

　　(3)英语中有很多表示比较的成语。 as black as coal as blind as a bat as brave as a lion as bright as day as busy as a bee as cold as ice as easy as ABC

　　as fat as a pig as hot as fire as light as air /a feather as like as two peas /beans as poor as a church mouse as rich as a Jew as sound as a bell状况极佳;十分健康 as fit as a fiddle as strong as a horse as stupid as a

　　donkey as sweet as honey /sugar as white as snow as red as blood as bright as a button as wise as Solomon

　　(五)含as的固定词组的用法

　　1.As soon as I get to Beijing，I'll write to you.我一到北京，就给你写信。

　　2.as/so long as作“只要”解，eg; As/So long as you study hard，you'll make progress. 比较：I've waited as long as two hours.我一直等了整整两小时。

　　3.as if/though常用来引导方式状语从句，作“好像，仿佛”解。如果从句中讲的是非

　　真实情况，则用虚拟语气。eg：She loves the child as if/though he were her own.

　　As if/though也可用来引导表语从句，常用在“It looks/seems...+as if/though”句型结构中。It looks to me as if/though it is going to clear up.It seems asif/though he knew nothing about it. You look as though you slept badly.

　　4.as to作“关于，至于”解。eg;There is no doubt as to his honesty.

　　5.as much/many as“多达…”，“达到…之多”eg：He can earn as much as 5000 dollars a month.

　　6.As/So far as I know，he will come here next Monday.据我所知，

　　比较：We might go as far as the school and back.我们可以走到学校那边，然后回来。

　　7.She died as a direct result of the accident.表示“由于...的结果”。

　　8，as well为“也，还”之意。eg： Come early，and bring your brother as well.

　　9.so as to，表示目的so...as to表示结果。eg：He studied hard so as to pass the exam.他努力学习以便通过考试。(表示目的)

　　10.as a matter of fact实际上，事实上 As a matter of fact，I'm very fond of house work.

　　11.as follows如下 Our plan is as follows.

　　12.as for至于，说到 As for me，I shall never return there.

　　13.as good as几乎已经，实际已经 Everything was as good as settled.一切都差不多安排好了. She is as good as her words.她遵守诺言。

　　He as good as said I'm a liar. 他无异于说我撒谎。

　　比较：Your composition is as good as his.你的`作文和他的作文一样好。

　　另外，还有以下习惯搭配，其翻译不能随便从字面来理解： (as) good as gold 表现很好的 (as) good as new 完好如新 as good as one’s word 守信

　　as good as pie 很好的，可爱的，讨人喜欢 (as) good as a play 非常有趣

　　14. as well as同样，和，也，而且 She called on you as well as I.不但我来看你，她也拜访了你。 She called on you as well as me. 她不但拜访了我，也拜访了你。

　　在下列句中，as well as表示“像一样”的涵义：She as well as you is an English teacher. 她像你一样也是英文教师。

　　George hasn’t gone abroad as well as his brother. 乔治并没有和他兄弟一样出国去。(他兄弟一人出国) George, as well as his brother, hasn’t gone abroad. 乔治和他兄弟都没有出国。

　　1) as well as 可连接并列的单词或短语前后两个动词的时态要一致。即：若第一个动

　　词是一般现在时，第二个动词也应是一般现在时;若第一个动词是一般过去时，第二个动词也应是一般过去时。例如：

　　He publishes(published)as well as prints(printed)his own books.他的书是自己印刷并出版的。

　　2)如果第一个动词是复合时态，或由can，may， must等加动词构成时，as well as后面可省去助动词或情态动词，此时，as well as意为“既又”。例如：

　　We are repairing the roof as well as painting the walls.我们在粉刷墙壁，同时也在修理屋顶。 She can /could sing as well as dance.她既会跳舞也会唱歌。

　　3)如果第一个动词是不定式，as well as后面的动词也要用不定式，但要去掉to。例如： You can't expect her to do the housework as well as look after the children.你不可能叫她既照管孩子又做家务。

　　⑷注意as well as的另外两层涵义：1)as well as还有“除之外”之意。例如： Aswell as knowing some Russian，she speaks English very well.除了懂得一点俄语之外，她的英语讲得很好。

　　比较：He can speak English as well as she does.他和她英语讲得一样好。

　　15.as many /much /deep /large，ect.as达……程度，多/深/大……达 As early ashis second film，Chaplin had developed his own manner of acting. 早在他第二部电影中，卓别林就形成了自己的表演风格。 The well is as deep as eight metres.这口井深达八米。

　　16.as usual像平常一样 She would go homeas usual for Christmas.

　　17.such as像……之类，例如 He knows a lot of poets ，such as Shelley and Byron.

　　18.may(might /could)as well不妨，不如 You may as well wait upstairs. you might as well throw the money into the sea as lend it to him.

　　19. as a rule作为一个常规,通常,习以为常?As a rule, we keep records on all the experiments so that we may have enough data.

　　20. As a whole作为一个整体(来看)?We should analyze the problem as a whole.

　　21. As above如上?It has been explained as above.?

　　22. as…as ever像往常一样……She works as hard as ever.她工作一贯努力。

　　23. as it is (was)①在句首,“但在实际上”;②在句末,“照原来样子”。As it was, we did help them.事实上,我们的确帮了他们。Leave the things as they are.别动这些东西。

　　24. as matters stand按目前情况来说 As matters stand, he does not like to make the plan public.就目前情况而论,他不愿公开那个计划。

　　AS用法总结

　　一、用作连词的as

　　1. 引导时间状语从句，表示“当……的时候”，其用法与when和while类似。例如：Asa child (When he was a child), she was sent to six different schools.此用法中as多表示从句与主句动作同时进行，意为“一边……一边……”，一般不与状态动词连用。例如：She sang songs as she did her homework.

　　as 还可以表示一动作紧接着另一动作发生，说明另一动作的结果，有“随着……”的含义。例如：As time went by, we found he was an honest man./As he grew older, he lost interest in everything except gardening.

　　例1 It wasn’t until nearly a month later________ I received the manager’s reply.

　　A. since B. when C. as D. that

　　解析：本题的as中与when一起作为干扰项，容易使考生往时间状语从句上思考，事实上本题是强调句，正确选项是D。

　　2. 引导原因状语从句，表示“由于，因为”，相当于because, 但通常置于句首。例如： As he is a qualified doctor, I trust his advice on medical matters.

　　例2 _____ modeling business is by no means easy to get into, the good model will always be in demand.

　　A. While B. Since C. As D. If

　　解析：本题中as干扰性很强，很多考生误以为是原因状语从句，但仔细分析不难发现正确答案应是A(while表示“只要”)。

　　3. 引导让步状语从句，通常可与although或though通用，但语序不同，although或though用于句首，as用于倒装结构。例如：Young as I am, I already know what career I want to follow. /Although(或Though)I am young, I already know what career I want to follow. as 表示让步用于倒装结构，通常将从句的表语、状语或动词前置。如果表语有冠词a/an, 需去掉。例如：Great scholar as he is, he is lacking in common sense./Much as I like you, I couldn’t live with you. 例3 _____ he has limited technical knowledge, the older worker has a lot of experience.

　　A. SinceB. Unless C. As D. Although

　　解析：as 虽然有引导让步状语从句用法，但本题不是倒装结构，故正确答案应是D。

　　4. 引导方式状语从句，表示“如，像”。例如：When in Rome, do as Romans do./Do to others as you would have others do to you.

　　例4 We wanted to get home before dark, but it didn’t quite ________ asplanned.

　　A. make outB. turn out C. go onD. come up

　　解析：本题考查动词词组辨析，题干中的“as planned”给同学们提供了重要信息，答案选B。

　　5. 固定句型：“主句，as +be/do+主语”表示“也一样”。例如：She’s unusually tall, as are both her parents./He’s a doctor, as was his wife before she had children.

　　二、用作介词的as

　　1.表示“如，像”。例如：They got united as one man./She spoke of me as her dearest friend.

　　2.表示“作为、当作”。例如：As a League member, you should think more of others.

　　3.与某些动词搭配，表示“把……当作……”，如：look on…as…, regard…as…, treat…as…, consider…as…, think of…as…, see…as…等。其中consider…as…中的as可以省略。as与famous或known搭配，表示“作为……而出名”。

　　例5 Linda worked for the Minnesota Manufacturing and Mining Company, ________ as 3M.

　　A. knowingB. known C. being knownD. to be known

　　解析：如果熟悉be known as这一短语，运用有关非谓语动词的常识，可选出正确答案B。

　　三、用作关系代词的as

　　1. 引导限制性定语从句，先行词前通常有as, so, such, same等修饰语。例如：He will marry as pretty a girl as he can find./My hometown is no longer the same asit used to be./As many people as are present will be given a present.在此种用法中，同学们要注意与结果状语从句的区别。比如：A: The teacher asked us such a difficult question that none of us could answer it. B: The teacher asked us such a difficult question as none of us could answer.A句为结果状语从句，而B句则是定语从句。

　　2. 引导非限制性定语从句，用来指代整个主句(即先行句)，表示“这一事实，那一情况”。从句可以位于句首、句中或句末。例如：We stand when the national anthem is played, as is the custom.

　　例6 ______ I explained on the telephone, your request will be considered at the next meeting.

　　A. When B. After C. As D. Since

　　解析：根据句意，选项C是正确答案。as表现的正是本点所讲用法。

　　四、用作副词的as

　　修饰形容词或副词，表示程度，意为“同样地”。例如：He swims fast, but I swim just as fast. 但它通常构成表示比较的结构“asas”，“not asas”。此结构中第一个as是副词，第二个as是连词。否定结构中的副词as可以由so代替。asas possible /one can也属于此用法。例如：It is generally believed that teaching is as much an art as it is a science.

　　五、用在习语中的as

　　由as构成的习语很多，常见的有：as soon as “一就”，引导时间状语从句;as/so long as “只要”引导条件状语从句;as if/though “好像，仿佛”，引导方式状语从句或表语从句;as to/ as for “至于，就而言”;as much/many as“多达”;as/so far as“就的限度”;as a result，as a result of “(由于的)结果”;as a matter of fact“事实上”;as well “也、还”;A as well as B“不但A而且B”;as it is“照现状看，看样子”，等等。这些习语在高考中可能经常遇到，在高考题中有的作为正确选项，有的作为干扰项，有的出现在题干，值得同学们认真掌握。例如：

　　例9 I would like a job which pays more, but ______ I enjoy the work I’m doing at the moment.

　　A. in other wordsB. on the other hand C. for one thing D. as a matter of fact 解析：选项D极具干扰意义，但进一步研读会发现本题中的两个分句表达了一件事的两个对立面，故选B。

　　例10 ——People should stop using their cars and start using public transport. ——______. The roads are too crowded as it is.

　　A. All right B. Exactly C. Go aheadD. Fine

　　解析：本题选项中虽没有as内容，但题干中的as it is却是解题的关键信息，正确选项为B。

　　限制性定语从句as 2

　　一、相同点

　　两者引导非限制性定语从句时，可指代主句中的部分或整个句子的内容，在从句中做主语，宾语或表语，位于主句之后有时可互换。

　　The meeting was put off, as /which was exactly what we wanted.

　　He was a doctor, as/which I knew from his manner.

　　二、不同点

　　1. as可以放在主句前后，也可插入主句之中；而which引导的非限制性从句只能位于主句之后。

　　As is known to all, fish can’t live without water.

　　Air, as we know, is gas.

　　2.在非限制性从句中，which后的be动词不可省；as而后的be动词可以省略。

　　She told me she won the match, which was a lie.

　　The material is elastic, as (was) shown in the figure.

　　3. which在非限制性定语从句做主语时可用各类动词做谓语；而as做主语时，谓语常用系动词，如be, seem, become等，一般不用其他行为动词。

　　He saw the girl, which delighted him.

　　He didn’t say anything at the meeting , as/which seemed very strange.

　　4. as常用“正如”含义，常用的结构有as we know（众所周知）；as often happens（正如常发生的那样）；as is often the case（情况常常如此）; as we all can see（正如我们看到的）; be announced/expected/known/imagined/mentioned/said/shown/

　　reported等。这些结构常放句首，偶尔也可以放句中或句末。

　　As is known to all, China is a developing country.

　　Kate was late for school, as often happened.

　　5. 在非限制性定语从句中which指代主句中某一个单词时，as不可以。

　　My brother enjoyed playing basketball, which he really plays well.

　　Beijing, which he was born in, is our capital.

　　6. “介词+关系代词（介宾代物）”中关系代词只能用which。

　　The Travel Agency, with which our company has been dealing for several years, has opened for new branches.

　　Air is a mixture of gases, of which oxygen forms 21 percent.

　　7. 从句中的谓语动词是否定形式时，常用which。

　　He can write a letter in English, which I can not.

　　Metal will bear beating with a hammer, which a stone will not