Before用法小结与考点解读.doc

Before用法小结与考点解读
Before用作连词时，意思是“在……之前”。其实，它引导状语从句时，在不同的句式中以及汉英表达习惯的不同，before含有不同的含义和用法。
从历年的高考试题可以看出，before是高考考查的热点词汇之一。为了帮助大家掌握，现就对它的用法归纳如下：
一、表示“在……之后……才”。副词“才”在汉语中强调某事发生得晚或慢。如果在含有before从句的复合句中，强调从句动作发生得晚或慢时，就可以应用这种译法。
The American Civil War lasted four years _______ the North won in the end2005广东)
    A. after B. before C. when D. then
    解析：答案为B。本题考查连词before表示“在……之后才……”之的用法，根据本句含义“美国南北战争持续了四年，北方才最终取得胜利”，可知本题应选B。
二、表示“……还没来得及……就……”。目的在于强调从句动作发生之前，主句动作已发生。
—Why didn't you tell him about the meeting? (2006四川卷)
— He rushed out of the room _________ I could say a word
A. before B. until C. when D. after
   解析：答案为A。本题考查连词before表示“……还没来得及……就……”的用法。句意是“我还没来得及说一句话，他就冲出了房间”。
三、表示“在……之前就……”。这时主句与before从句中的两个动作按时间先后依次发生。
It was evening______ we reached the little town of Winchester. （2004天津）
A. that B. until C. since D. before
   解析：答案为D。本题考查连词before表示“在……之前就……”的用法。句意是“我们到达小镇Winchester之前就已经是傍晚时分了”。
四、表示“趁……”，“等到……”，或 “没等……就…… ”等。
He made a mistake, but then he corrected the situation _____ it got worse.（2003北京）
A. until B. when C. before D. as
解析：答案为C。由made a mistake和转折词but可知本题句意是“他出了差错 但没等其进一步恶化，他就调整了局势”。故正确答案为C项。
五、用于句型“It + will/would be + 时间段 + before...”句型中，表示“要过多久才…”，也可用于“It + may be + 时间段 + before...”，表示“也许要过多久才……”。其否定形式“It will/would not be +时间段+ before…”表示“不久就……，过不了多久就……”。
（1）The field research will take John and Paul about five months; it will be a long time _____ we meet them again.（2007安徽卷）
A. after B. before C. since D. when
（2）—How long do you think it will be ______China sends a manned spacesship to the moon? （2006福建卷）
—Perhaps two or three years.
A. when B. until C. that D. before
（3）It ________ long before we _______ the result of the experiment.( 上海春招2002)
A. will not be...will know B. is...will know
C. will not be...know D. is...know
(4) Scientists say it may be five or six years_________ it is possible to test this medicine on human patients. （2004福建）
A. since B. after C. before D. when
解析：答案为BDCC。考题（1）(2)before 用于肯定的“It + will be + 时间段 + before...”句型中，表示“要过多久…才…”。考题（3）before在本题中用于否定句,意为“过不了多久就会……”,再由状语从句要用一般现在时态替一般将来时的用法可知C项为正确答案,句意是:要不了多久我们就会知道试验的结果了。考题（4）宾语从句中含有句型“It + may be + 时间段 + before...”，表示“也许要过多久才……”，故选择答案C。
六、用于句型 “it was +时间段+ before …” 表示 “过了（多长时间）才……”。其否定形式“ it was not +时间段+ before …” 意为“不久就……”, “没过（多长时间）就……”。
It was some time ___________we realized the truth. （2005山东）
A. when B. until C. since D. before
解析：答案为D。before用于句型“it was +时间段+ before …” 表示 “过了（多长时间）才……”。该题题意是“过了一段时间我们才意识到事情的真相”。故正确答案为C项。
七和hardly连用，表示“刚一……就……”。该结构主句常用过去完成时，当hardly位于句首时，要用倒装语序，例如：
 I had hardly sat down before the telephone rang.
Hardly had I sat down before the telephone rang.
我刚一坐下电话就响了。
八、和其它相似句型的区别
有时候before引导的时间状语从句与since，when引导的时间状语从句在下列结构中较相似，容易混淆。
“It be +时间段 + since引导的时间状语从句”表示“自从……已经有多长时间了”。主句用一般现在时或现在完成时。
“It be +时间点 +when引导的时间状语从句”表示“某个动作发生时，是某个时间”。主句谓语动词可以是一般过去时，也可以是一般将来时。
（1）It is almost five years we saw each other last time. （2005北京春）
A. before B. since C. after D. when
（2）— Did Jack come back early last night? （2005福建）
— Yes. It was not yet eight o’ clock________ he arrived home.
A. before B. when C. that D. until
解析：答案为BB。考题（1）考查的是“It be +时间段 + since引导的时间状语从句”结构，句意是“自从上次我们见面以来已经近五年没有见了”，故选择答案B。考题（2）考查的是句型“It be +时间点 +when引导的时间状语从句”，句意是“他昨晚回家时还不到8点”，故选择答案B。
九、before long和long before的区别
before long意为“不久，很快”（其中before是介词，long是名词），常在句中作状语，多与动词的过去时或将来时连用。例如：
The work will be finished before long. 工作不久就会完成。
Before long he had to move on again. 不久，他被迫再次迁移。
long before意为“很久以前”（其中long是副词。long before单独使用时， before是介词；long before后接从句时，before是连词。）这个词组常与过去时或过去完成时连用，跟从句时也可用在一般现在时的句子中。例如：
She said that she had heard of it long before. 她说她早就听说过此事。
It will be long before he arrives. 还要等很久他才能到达。
巩固练习
一、选词填空
1. before long/long before
(1) __________he went to America.
(2) I hope to see you ____________.
(3) She said she had read the novel ______________.
(4) I had not waited ______________ she came.
（5）It was not __he got to know it.
2. before/since/when
(1) It was four 0’clock _______ they arrived at the town.
(2) It has been 3 years__________ his brother went abroad for further study.
(3) It will be more than a week __________ his mother recovers from the disease.
二、翻译下列句子
1. 不等我说一句话，她就冲出了房间。
2. 他叔叔五年后才能回来。
3. 不久之后，敌人就被赶走了。
4. 他们不久就会互相了解的。
5. 他们正在考虑趁房价未涨时把房子买下来。
6. 我没等多久她就来了。
7. 我们还需要很长时间才能完成这项任务。
8. 不久他就学会使用计算机了。
9. 过了一段时间之后他告诉了我这件事。
10. 不久之后我们还会再见面的。
11. 大火烧了近四个小时，消防战士才把它控制住。
12.不久你就会对你的所作所为感到后悔的。
13. 他刚一开口发言，就被其他人打断了。
14. 不久他就知道了
三、单句改错
1. It was some time since they realized the importance os studies.
2. It was at midnight when her husband came back home last night.
3. It was about five hours when the workers shipped all the goods.
4. We will finish the work long before. .
5. It will be half a year before his brother will graduate from that college.
6. I had known her before long.
四、单项选择
1. —Why didn't you tell him about the meeting ?
— He rushed out of the room _________ I could say a word.
A. before B. until C. when D. after
2. —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. that D. before
3 .He was told that it would be at least three more months he could recover and return to work.
A. when B. before C. since D. that
4. Several weeks had gone by______ I realized the painting was missing.
A. as B. before C. since D. when
5. Scientists say it may be five or six years_________ it is possible to test this medicine on human patients.
A. since B. after C. before D. when
6. The American Civil War lasted four years ________ the North won in the end.
A. after B. before C. when D. then
7. That was really a splendid evening. It’s years ______ I enjoyed myself so much.
A. when B. that C. before D. since
8. It was some time ___________we realized the truth.
A. when B. until C. since D. before
9 .He was told that it would be at least three more months he could recover and return to work.
A. when B. before C. since D. that
10. —Where’s that report?
—I brought it to you ____you were in Mr. Black’s office yesterday.
A. if B. when C. because D. before

Keys:
一、选词填空
1. (1) Before long (2) before long (3) long before (4) long before (5) long before
2. (1) when (2) since (3) before
二、翻译下列句子
1. She had stormed out of the room before I could say a word
2. It will be five years before his uncle comes back.
3. It was not long before the enemy was driven out of their country.
4. It won’t be long before they understand each other.
5. They are thinking of buying the house before the prices go up.
6. I had not waited long before she came.
7. It will be a long time before we finish the task.
8. It wasn’t long before he learned to use the computer.
9. It was some time before he told me about this affair.
10. It won’t be long before we meet again.
11. The fire lasted about four hours before the firefighters could control it
12. It won’t be long before you feel sorry for what you have done.
13. He had hardly begun to speak before the others interrupted him.
或Had he begun to speak before the others interrupted him.
14. It was not long before he got to know it.
三、单句改错
1. since改为before或was改为is
2. when改为that或去掉at
3. when改为before
4. long before改为before long
5. will graduate改为graduates.
6. before long改为long before
四、单项选择
1～5 ABBBC 6～10 BDDBB
before 的用法
27 The most destructive natural disaster, tsunami, came unexpectedly_________ they will always live in peace and comfort.
A after B while C where D when
before 的用法:
(1) (时间) 在……之前, (位置) 在……的前面
(2) ……才……, (强调before引导的从句动作发生的很晚很迟),例如:
He nearly knocked me down before he saw me.
(3) 还未来得及/不等……就……(强调主句动作发生在before引导的从句动作之前), 例如:
He went out before I had a chance to tell him the good news.
(4) 不久…… 就,例如:
It won’t be long before you get well again.
(5)宁愿……也不……, 例如:
He will die of hunger before he will steal.
考例:
(NMET 2000) Some one called me up in the middle of the night, but they hung up_____ I could answer the phone.
A as B since C until D before
(03 北京) He made a mistake, but then he corrected the situation______ it got worse.
A until B when C before D as
(04 天津) It was evening_______ we reached the litter town of Winchester.
A that B until C since D before
(04 福建) Scientists say it may be five or six years____ it is possible to test this medicine on human patients.
A since B after C before D when
(05 广东) The American Civil War lasted four years____ the North won in the end.
A after B before C when D then
(03 江苏调研)----Why didn’t you help the little boy?
-----Oh, sorry. He had struggled to his feet____ I ran over.
A until B after C before D since
(05 辽宁联考)He had to be called two or three times_____ he would come to his dinner.
A before B when C until D as
(苏锡常镇一) She was such a proud person that she would die_____ she would admit she was wrong.
A rather than B until C after D before
It has been announced that it won’t be long______ our country______ an unmanned spaceship to explore the moon.
A before; sends up B until; sends up
C since; sends up D before; will send up