when-before-since區(qū)別及用法PPT優(yōu)秀課件

1、when,before,since句型歸納 1、when 句型：句型：(1) be doing sthwhen He was still smiling when the door opened and his wife came in. 他正笑著的時(shí)候門(mén)突然開(kāi)了，他妻子走了進(jìn)來(lái)。(2) be about to do sthwhen We were about to start when it began to rain. 我們剛要出發(fā)，天就開(kāi)始下雨了。(3)be on the point of doingwhen正要正要這時(shí)這時(shí) We were on the ponit of giving

2、up when a truck came into our sight. 我們正要放棄，這時(shí)看到了一輛卡車(chē)。我們正要放棄，這時(shí)看到了一輛卡車(chē)。(4)hardly /sceracelywhen(一一就就) He had /hardly/scarcely fallen asleep when the telephone rang. 他剛要入睡電話就響了。(5) had just done when (剛做完剛做完某事發(fā)生某事發(fā)生)I had just gone to bed after a very hard day when the phone rang. 在勞累了一天之后我剛剛就寢，電話鈴就響

3、了。(6)還可以表示原因還可以表示原因“既然既然”，相當(dāng)于，相當(dāng)于since; considering that. It was foolish of you to take a taxi when you could easily walk there in five minutes .(4)hardly /sceracelywhen(一一就就) He had not/hardly/scarcely fallen asleep when the telephone rang. 他剛要入睡電話就響了。We had scarcely arrived when he asked us to lea

4、ve.我們才剛剛到他就叫我們走了. before sb can/ could 某人還沒(méi)來(lái)得及某人還沒(méi)來(lái)得及Before I could get in a word ，he had measured me 我還沒(méi)來(lái)得及插話，他就給我量好了尺寸我還沒(méi)來(lái)得及插話，他就給我量好了尺寸 It will be/was +時(shí)間段時(shí)間段+ before 過(guò)一段時(shí)間過(guò)一段時(shí)間才才 It will be 4 years before he graduates. 他還有四年時(shí)間畢業(yè)了。他還有四年時(shí)間畢業(yè)了。 It was 5 minutes before he left.過(guò)過(guò)5分鐘才離分鐘才離開(kāi)開(kāi) 2.before

5、句型句型 It wont be long before.（從句用現(xiàn)在時(shí)）（從句用現(xiàn)在時(shí)） It wasnt longbefore.（從句用過(guò)去時(shí)）（從句用過(guò)去時(shí)）沒(méi)過(guò)多久沒(méi)過(guò)多久/用不了多久用不了多久就就eg:It wasnt long before i found a job.It wont be long before our contry becomes a developed country.我們國(guó)家很快就會(huì)成為一個(gè)我們國(guó)家很快就會(huì)成為一個(gè)發(fā)達(dá)國(guó)家。發(fā)達(dá)國(guó)家。 before long (adv.)不久，不久，long before 很久以前很久以前 (3) had done befor

6、e （才（才） We had sailed four days and four nights before we saw land. 我們航行了四天四夜才見(jiàn)到陸地。我們航行了四天四夜才見(jiàn)到陸地。 (4) had not done - before - 不到不到就就 We hadnt run a mile before he felt tired. 我們還沒(méi)走到一英里路他就覺(jué)得累了。我們還沒(méi)走到一英里路他就覺(jué)得累了。 It is/has been時(shí)間段時(shí)間段since sb. diddid動(dòng)作為瞬間動(dòng)詞（非延續(xù)性），翻譯動(dòng)作為瞬間動(dòng)詞（非延續(xù)性），翻譯為自從某事發(fā)生以來(lái)有多長(zhǎng)時(shí)間為自從某事發(fā)生

7、以來(lái)有多長(zhǎng)時(shí)間 It is 5 years since he left Beijing . 他離開(kāi)北京他離開(kāi)北京5年了年了It has been 3 years since he came back from abroad.自從他回國(guó)已經(jīng)三年了自從他回國(guó)已經(jīng)三年了 3.since句型句型 It is/has been時(shí)間段時(shí)間段since sb. diddid動(dòng)作為持續(xù)動(dòng)詞（延續(xù)性），翻譯為動(dòng)作為持續(xù)動(dòng)詞（延續(xù)性），翻譯為自從不做某事有多長(zhǎng)時(shí)間自從不做某事有多長(zhǎng)時(shí)間 It has been 5 years since he was a student .他不當(dāng)學(xué)生有他不當(dāng)學(xué)生有5年了年了It

8、is 5 years since he lived in beijing . 他不在北京居住有他不在北京居住有5年了年了 3.since句型句型1. (04北京春) We were swimming in the lake _ suddenly the storm started. A. whenB. whileC. untilD. before2. (02上海) He was about to tell me the secret _ someone patted him on the shoulder. A. as B. untilC. whileD. when3. (05上海) He t

9、ransplanted the little tree to the garden _ it was the best time for it. A. whereB. when C. thatD. until5. (06遼寧) He was about halfway through his meal _ a familiar voice came to his ears. A. why B. where C. when D. whileExercises:A. whenD. whenB. whenB. whenC. when6. (06天津) The cost of living in Gl

10、asgow is among the lowest in Britain, _ the quality of life is probably one of the highest. A. since B. when C. as D. while7. (04年江蘇) _ I accept that he is not perfect, I do actually like the person. A. While B. Since C. Before D. Unless D. A. 8._ entered the office when he realized that he had forg

11、otten his report. A. He hardly had B. Had he hardly C. Hardly had heD. Hardly he had C9. (03年北京) He made a mistake, but then he corrected the situation _ it got worse. A. untilB. whenC. beforeD. as10. (04福建) Scientists say it may be five or six years _ it is possible to test this medicine on human patients. A. sinceB. afterC. beforeD. when11. (06四川)Why didnt you tell him about the meeting?He rushed