when-before-since区别及用法课件

1、when-before-since区别及用法,when,before,since句型归纳,when-before-since区别及用法,1、when 句型：(1) be doing sthwhen He was still smiling when the door opened and his wife came in. 他正笑着的时候门突然开了，他妻子走了进来。(2) be about to do sthwhen We were about to start when it began to rain. 我们刚要出发，天就开始下雨了。(3)be on the point of doingw

2、hen正要这时 We were on the ponit of giving up when a truck came into our sight. 我们正要放弃，这时看到了一辆卡车。,when-before-since区别及用法,(4)hardly /sceracelywhen(一就) He had /hardly/scarcely fallen asleep when the telephone rang. 他刚要入睡电话就响了。 (5) had just done when (刚做完某事发生)I had just gone to bed after a very hard day wh

3、en the phone rang.在劳累了一天之后我刚刚就寝，电话铃就响了。 (6)还可以表示原因“既然”，相当于since; considering that. It was foolish of you to take a taxi when you could easily walk there in five minutes .,when-before-since区别及用法,(4)hardly /sceracelywhen(一就) He had not/hardly/scarcely fallen asleep when the telephone rang. 他刚要入睡电话就响了。

4、 We had scarcely arrived when he asked us to leave. 我们才刚刚到他就叫我们走了.,when-before-since区别及用法,before sb can/ could 某人还没来得及Before I could get in a word ，he had measured me我还没来得及插话，他就给我量好了尺寸 It will be/was +时间段+ before 过一段时间才 It will be 4 years before he graduates. 他还有四年时间毕业了。 It was 5 minutes before he l

5、eft.过5分钟才离开,2.before句型,when-before-since区别及用法,It wont be long before.（从句用现在时） It wasnt longbefore.（从句用过去时） 没过多久/用不了多久就 eg:It wasnt long before i found a job. It wont be long before our contry becomes a developed country.我们国家很快就会成为一个发达国家。 before long (adv.)不久，long before 很久以前,when-before-since区别及用法,(

6、3) had done before （才） We had sailed four days and four nights before we saw land. 我们航行了四天四夜才见到陆地。 (4) had not done - before - 不到就 We hadnt run a mile before he felt tired. 我们还没走到一英里路他就觉得累了。,when-before-since区别及用法,It is/has been时间段since sb. did did动作为瞬间动词（非延续性），翻译为自从某事发生以来有多长时间 It is 5 years since h

7、e left Beijing . 他离开北京5年了 It has been 3 years since he came back from abroad.自从他回国已经三年了,3.since句型,when-before-since区别及用法,It is/has been时间段since sb. did did动作为持续动词（延续性），翻译为自从不做某事有多长时间 It has been 5 years since he was a student . 他不当学生有5年了 It is 5 years since he lived in beijing . 他不在北京居住有5年了,3.since句

8、型,when-before-since区别及用法,1. (04北京春) We were swimming in the lake _ suddenly the storm started. A. whenB. whileC. untilD. before 2. (02上海) He was about to tell me the secret _ someone patted him on the shoulder. A. as B. untilC. whileD. when 3. (05上海) He transplanted the little tree to the garden _ i

9、t was the best time for it. A. whereB. when C. thatD. until 5. (06辽宁) He was about halfway through his meal _ a familiar voice came to his ears. A. why B. where C. when D. while,Exercises:,A. when,D. when,B. when,B. when,C. when,when-before-since区别及用法,6. (06天津) The cost of living in Glasgow is among

10、 the lowest in Britain, _ the quality of life is probably one of the highest. A. since B. when C. as D. while 7. (04年江苏) _ 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 forgotten his rep

11、ort. A. He hardly had B. Had he hardly C. Hardly had heD. Hardly he had,C,when-before-since区别及用法,9. (03年北京) He made a mistake, but then he corrected the situation _ it got worse. A. untilB. whenC. beforeD. as 10. (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. when 11. (06四川)Why didnt you tell him about the meeting? He rushed out