since,before,when,after等的區(qū)別

1、高考英語?？季涫絠t is +時(shí)間+ since (before, when)請注意以下三個(gè)句式的區(qū)別和意思上的差異（其中的is根據(jù)情況可以有其他時(shí)態(tài)形式）：It is +時(shí)間段 + since的意思是“自從 以來有一段時(shí)間了”。It is +時(shí)間點(diǎn) + when的意思是“當(dāng) 的時(shí)候時(shí)間是 ”。It is +時(shí)間段 + before的意思是“在 之前有一段時(shí)間”。請看以下用例：It s ten years since they got married.他們結(jié)婚到現(xiàn)在已經(jīng)十年了。It was past one oclock when he came in.他回來時(shí)已經(jīng)一點(diǎn)多了。It won t

2、be long before they understand each other.過不了多久他們就會(huì)互相了解的。有時(shí)翻譯可以比較靈活：It s a long time since I met you last.好久不見了。( 直譯：自上次見到你以來有很長一段時(shí)間了。 )It s about three years since I last played basketball.譯：自從我上次打籃球以來已差不多有三年了。)我差不多有三年沒有打籃球了。( 直請看有關(guān)高考題( 答案為DDBCDC)：1.That was really a splendid evening. It s years _

3、I enjoyed myself so much.(安徽卷 )beforeA.whenB.thatD.sinceC.ince2.A.It was some time _we realized the truth. (whenB.untilD.before山東卷)C.s3. Did Jack come back early last night?Yes. It was not yet eight o A. beforeclock _he arrived home. (B.whenD.until福建卷 )C.that4.Scientistssay it may be fiveorsix years

4、_it is possible totest thismedicineon human patients. (福建卷 )A.sinceB.afterC.beforeD.when5.It was eveningwe reached the little town of Winchester. (天津卷 )A.thatB. untilC. sinceD. before6.It _ long before we _ the result of the experiment. (上海春 )A.will not be; will knowB.is; will knowC.will not be; kno

5、wD.is; know【全真模擬訓(xùn)練】1. It was about midnight _ we found the lost child, crying under a tree.A.thatB.untilC.whenD.where2. Its some time _ I have spoken to you about this matter.A.thatB.unlessC.sinceD.until3.It was ten _ he stood at aunts door and rang the bell.A.whenB.untilC.sinceD.that4. I think it w

6、on t be long _ they understand each other.A.whenB.untilC.sinceD.before5. How pleased I am tonight! ItA. whens years _ we had so great a time together.B.thatC.beforeD.since6. It was some time _ we realized how important the matter is.A.whenB.untilC.sinceD.before7. Did you come home very late last nig

7、ht?No. It was just half past seven _ I appeared before my parents.A.thatB.whenC.untilD.since8. How time files! It seems like years _ I last saw you.nceA.whenB.thatD.beforeC.si9.A.It s more than half whena century_ the People s RepublicB.thatof China was liberated.C.sinceD.after答案： 1 5 CCADD6 9 DBCCw

8、hen引導(dǎo)時(shí)間狀語從句具體地說，它有以下幾種含義：1表明一個(gè)動(dòng)作發(fā)生的時(shí)候，另一個(gè)動(dòng)作正在進(jìn)行之中。例如：When the teacher came into the classroom，we were reading English當(dāng)老師走進(jìn)教室時(shí)，我們正在讀英語。2表明當(dāng)某一動(dòng)作正在進(jìn)行時(shí)，另一動(dòng)作發(fā)生了。如：When Kate was flying a kite，she found a wallet lying on the ground凱特正在放風(fēng)箏時(shí)，她發(fā)現(xiàn)地上有個(gè)錢包。特別提示當(dāng)when 從句放在主句之后時(shí)，它更強(qiáng)調(diào)某一動(dòng)作的突然性，此時(shí)的when 相當(dāng)于 and thenand

9、suddenly ，just at that time。如；1We were watching TV when the telephone rang（ We were watching TV and suddenly the telephone，rang ）我們正在看電視，（突然）電話鈴響了。試比較： When we were watching TV， the telephone rang我們正在看電視時(shí)，電話鈴響了。2The boys were playing football when it began to rain男孩子們正在踢球時(shí)，（不料）開始下雨了。3 I was taking a

10、 walk when I came across Lily我正在散步時(shí)，（沒想到）遇見了莉莉。特別是主句中有just ，或 when 從句中有 suddenly 時(shí)，這種突然性更為明顯、強(qiáng)烈。Until直到 .為止 , notuntil直到才肯定形式表示的意思是做某事直至某時(shí) ，動(dòng)詞必須是延續(xù)性的。否定形式表達(dá)的意思是 直至某時(shí)才做某事 。動(dòng)詞為延續(xù)性或非延續(xù)性都可以?？隙ň洌篒 slept until midnight.我一直睡到半夜時(shí)醒了。Wait till I call you.等著我叫你。（在肯定句中可用before代替 Let ”s get in the wheat before t

11、he sun sets.）否定句：She didn ” t arrive until 6 o” clock.她直到 6 點(diǎn)才到。否定句可用另外兩種句式表示。(1)Not until在 句首，主句用倒裝。Not until the early years of the 19th century did man know what heat is.直到 19 世紀(jì)初，人類才知道熱能是什么。Not until I began to work did I realize how much time I had wasted.直到我開始工作，我才認(rèn)識(shí)到了我已蹉跎了幾多歲月。(2) It is not u

12、ntil這that是一 個(gè)強(qiáng)調(diào)結(jié)構(gòu)。如本題。before引導(dǎo)的從句不再用否定式的謂語，并且當(dāng)before 引導(dǎo)的從句位于主句之后，有時(shí)譯成“就，才 ”。還要注意主句和從句之間的時(shí)間關(guān)系。當(dāng)主句用將來時(shí)，從句總是用現(xiàn)在時(shí)；如果before 引導(dǎo)的從句謂語用的是過去時(shí)，則主句動(dòng)詞多用過去完成時(shí)，這樣以便體現(xiàn)動(dòng)作發(fā)生的先后。It will be four days before they come back.他們要過四天才能回來。Einstein almost knocked me down before he saw me.愛因斯坦幾乎把我撞倒才看到我。before 作為連詞的用法其基本含義是 “

13、在之前 ”，又可以根據(jù)不同語境靈活翻譯成“才 ”、 “還沒來得及就 ”、“趁 ”、“就”等。具體用法如下：) 與情態(tài)動(dòng)詞can/could連用這時(shí)候從句雖為肯定形式，根據(jù)漢語表達(dá)習(xí)慣譯成“還沒來得及就 ”， 目的在于強(qiáng)調(diào)從句動(dòng)作發(fā)生之前，主句動(dòng)作已發(fā)生。如： Before I could get in a word，he had measuredme. 我還沒來得及插話他就為我量好了尺寸。Before she could move，she heard a loud noise，whichgrew to a terribl eroar她還沒來得及邁步，就聽見一聲巨響，接著就是可怕的隆隆轟鳴。)

14、用于肯定句中強(qiáng)調(diào)主句所表達(dá)的時(shí)間，距離長，或花費(fèi)的精力大， 譯成 “才” We had sailed four days andfour nights before we saw lands.我們航行了四天四夜才看到陸地。We waited a long time beforethe train arrived.我們等了很長時(shí)間火車才到。) 用于否定句中，強(qiáng)調(diào)主句所表達(dá)的時(shí)間，距離短，或花費(fèi)的精力小，譯成“不到就”如： We hadntrun a mile before he felt tired.我們跑了還不到一英里他就累了。) 主句含有 hardly ，scarcely 等半否定副詞時(shí)可以

15、譯為“剛就”這時(shí)候主句應(yīng)用過去完成時(shí)態(tài)，從句用過去時(shí)，還可以用 when 替代 before 如： We had scarcely reached the school before/when the bellrang.我們剛到學(xué)校鈴聲就響了。) 有時(shí)還有 “寧愿 ”的意思I d shoot myself before I apologized to him.我寧死也不向他道歉。) 用于 It+be/take+ 時(shí)間段 +before 句型在這一句型中又可以根據(jù)主從句的時(shí)態(tài)分成兩種情況。若主句是一般時(shí)將來時(shí)態(tài)，從句是一般現(xiàn)在時(shí).若主句是肯定句意思是“要過多長時(shí)間才”；若主句是否定形式翻譯成 “

16、用不了多久就 ”。 It will be two weeks before everything returns to normal.兩周之后一切才能恢復(fù)正常。It will be many years before the situation improves.這種狀況或許要過許多年才能得以改善。It won t be long before we meet again. 用不了多久我們就會(huì)再見面的。這時(shí)若主句是一般過去時(shí)從句也是一般過去時(shí)。若主句是肯定句翻譯成“多長時(shí)間之后才”，若主句是否定形式翻譯成“沒過多久就 ”。如： It was some time before I realize

17、d the truth.過了很長一段時(shí)間我才了解到真相。It wasn tlong before she became a brave solider.沒過多久她就成了一名勇敢的戰(zhàn)士。After that it still tookseven years before they got married.他們又過了七年才結(jié)婚。注意：當(dāng)主句的謂語動(dòng)詞為延續(xù)性動(dòng)詞時(shí)， before 與 until 有時(shí)可以互換。 It was an hour before/until the police arrived.) 和其它相似句型的區(qū)別有時(shí)候 before 引導(dǎo)的時(shí)間狀語從句與since ， when 引

18、導(dǎo)的時(shí)間狀語從句在下列結(jié)構(gòu)中較相似，容易混淆?！癐t be +時(shí)間段+ since 引導(dǎo)的時(shí)間狀語從句”表示 “自從已經(jīng)有多長時(shí)間了 ”。主句用一般現(xiàn)在時(shí)或現(xiàn)在完成時(shí)。如：It s two years since we arrived here.我們到這兩年了?！癐t be +時(shí)間點(diǎn)+when 引導(dǎo)的時(shí)間狀語從句”表示 “某個(gè)動(dòng)作發(fā)生時(shí)，是某個(gè)時(shí)間”。主句謂語動(dòng)詞可以是一般過去時(shí)，也可以是一般將來時(shí)。如：It s Dec 18 when I was born.我出生于 12 月 18號(hào)。) before long和 long before的區(qū)別before long意為 “不久，很快 ”（其中

19、 before 是介詞， long 是名詞），常在句中作狀語，多與動(dòng)詞的過去時(shí)或?qū)頃r(shí)連用。例如：The work will be finished before long.工作不久就會(huì)完成。long before意為 “很久以前 ”（其中 long 是副詞。 long before單獨(dú)使用時(shí)， before是介詞； long before后接從句時(shí)， before 是連詞。）這個(gè)詞組常與過去時(shí)或過去完成時(shí)連用，跟從句時(shí)也可用在一般現(xiàn)在時(shí)的句子中。例如：She said that she had heard of it long before.她說她早就聽說過此事。It will be lon

20、g before he arrives.還要等很久他才能到達(dá)。before 引導(dǎo)的從句不再用否定式的謂語，并且當(dāng)before 引導(dǎo)的從句位于主句之后，有時(shí)譯成“就，才 ”。還要注意主句和從句之間的時(shí)間關(guān)系。當(dāng)主句用將來時(shí)，從句總是用現(xiàn)在時(shí)；如果before 引導(dǎo)的從句謂語用的是過去時(shí)，則主句動(dòng)詞多用過去完成時(shí)，這樣以便體現(xiàn)動(dòng)作發(fā)生的先后。After 表示主句動(dòng)作發(fā)生在從句動(dòng)作之后。主句和從句的動(dòng)作的時(shí)間關(guān)系正好與before 引導(dǎo)的從句相反。練習(xí) (2004 天津 )It was evening _ we reached the little town of Winchester.A . th

21、at B.until C.since D.when2.(2004 全國 )Several weeks had gone by _ we realized the painting was missing.A.as B.before C.since D.when3.(2005 廣東 )The America Civil War lasted four years _ the North won in the end.A.after B.before C.when D.then4.(2005 山東 )It was some time _ we realized the truth.A.when B

22、.until C.since D.before5.(2006 四川 )-Why didn t you tell him about the meeting？ -He rushed out of the classroom _ Icould say a word.A.before B.until C.when D.after6.(2006 福建 )-How long do you think it will be _ china sends a manned spaceship to the moon？-Perhaps two or three years.A.when B.until C.th

23、at D.before參考答案： DBBDADsince一、若主句的謂語動(dòng)詞是現(xiàn)在時(shí)態(tài)，從句的謂語動(dòng)詞是非持續(xù)性動(dòng)詞，則從句的動(dòng)詞只能用一般過去式：IIt is(or has been)two months since he fell ill (不能用 has or hadfallen i11)( 自)他生病 ( 以來 )已有兩個(gè)月了。2 It has been(or is)about ten minutes since the film began (不能用 hasor had begun)( 自 )電影開演 (到現(xiàn)在 ) 大約已有 10 分鐘了。二、若主句和從句的謂語動(dòng)詞都是過去時(shí)態(tài)，從句

24、的謂語動(dòng)詞又是非持續(xù)性動(dòng)詞，主句和從句的謂語動(dòng)詞時(shí)態(tài)搭配則有四種情況：IIt was two months since he fell ill( 自)他生病 (以后 )到那時(shí)已有兩 個(gè)月了。 (以下三句的譯文跟該句相同)2It had been two months since he had fallen i113 It had been two months since he fell i114 It was two months since he had fallen ill三、若主句的謂語動(dòng)詞是現(xiàn)在時(shí)態(tài)，從句的謂語動(dòng)詞是持續(xù)性動(dòng)詞的過去時(shí)形式， since 從句表示的時(shí)間應(yīng)從該從句動(dòng)詞的

25、終點(diǎn)算起：IIt is(or has been)two months since he was ill(was ill=got well)(自 )他病愈 ( 以來 )已有兩個(gè)月了。2 It is(or has been)two months since he lived here (1ived here=movedaway)( 自) 他搬走 ( 至今 )已有兩個(gè)月了。四、若主句的謂語動(dòng)詞為現(xiàn)在時(shí)態(tài)，從句的謂語動(dòng)詞是持續(xù)性動(dòng)詞的現(xiàn)在完成時(shí)形式，則since 從句所表示的時(shí)問，要從該持續(xù)動(dòng)詞的起點(diǎn)算起：1.Its(or has been)two months since he has beenil

26、lhas been ill=fellill)( 自)他生病 (以來 )已有兩個(gè)月了。2 Its(or has been)two months since he has lived here(has livedhere=moved here)(自)他搬到這兒居住(以來 )已有兩個(gè)月了。五、若主句的謂語動(dòng)詞是過去時(shí)態(tài)，從句的謂語動(dòng)詞用持續(xù)性動(dòng)詞的過去式跟用其過去完成時(shí)形式意義相反：IIt had been(or was)two months since he had lived here（ had livedhere=moved here)(自)他搬來居住 (到那時(shí) ) 已有兩個(gè)月了。2 It h

27、ad been(or was)two months since he lived here (1ived here=movedaway)( 自) 他搬走 ( 那時(shí) )已有兩個(gè)月了。（1）when. 當(dāng) 的時(shí)候，when 從句謂語動(dòng)詞可為延續(xù)性動(dòng)詞或非延續(xù)性動(dòng)詞。Eg. I was listening to MP3 when my friend arrived. Eg. When I was young, I would go hunting with my father in the forest. when 可作并列連詞，連接兩分句，意為“就在/ 剛好那時(shí)”。Eg. Jim was on h

28、oliday with his mother in a wildlife park when a poisonous snake bit him.(2)while. 在 的時(shí)候。注意while 從句須用延續(xù)性動(dòng)詞。Eg. While I was sweeping the floor, Mr. Zhou walked in. eg. _she left her hometown, it was snowing hard.A. WhenB. whileC. afterwhile 可作并列連詞，表示比較或?qū)Ρ?。意為“? 卻/ 可是”eg. Mother often takes a bus to w

29、ork_Father usually goes by car.Eg. We Chinese like using chopsticks_westerners prefer knives and forks.A.whenB. whileC. becauseD. since E. that(3) before. 在 之前。主句謂語動(dòng)詞先于從句的謂語動(dòng)作之前。before還有其它的意思“還要過多少時(shí)間/ 過了多少時(shí)間才 ”eg. He covered not more than 5 miles_it began to rain heavily.Eg. Ten years had passed_he realized he hadn t learned much.Eg. It wont be long_Mother returns home.Eg. The boy was run over by the train_she could save him.A. after B. beforeC. whenD. since