before用法.doc

before 的用法before 的用法 1 作介词A．指时间．在……以前．　e.g. It began to rain before midnight .B. 指位置．在 ……面前．　e.g. They knelt before the king .C. 指顺序或排列在前面．　e.g. You name comes before mine on the list .2 作连词A．在…… 之前．　e.g. Did she leave a message before she went ?B．用于 It + be +时间段 + before ：在……之后才……　　e.g. It willl be five years before I come back .3 常于情态动词 can / could 连用 ：　还没来得及……就……e.g. Before I could say a word , she had rushed out of the room 掌握 before 热点用法 1. prep. 在...... 以前，强调时间 He came to see me the day before yesterday. 他前天来看我了。

2. prep. 在...... 前面，当着......的面，向......，强调地点 She has to appear before the court. 她必须出庭受审 3. prep. 在...... 之前，先于，强调次序 Those with babies can get on the bus before others. 带小孩的人可以先上汽车 4. prep. 与其...... （宁愿） I'd shoot myself before I apologized to him! 我宁死也不向他道歉! 5. adv. 以前，强调时间 We've seen that film before. 我们以前看过那场电影 6. adv. 在前面，向前，强调位置 Don't run before and after. 别跑前跑后 7. conj. 在......前，强调时间 before 的含义比较灵活，实际翻译时应结合具体情况机动处理1. 趁 ...... You should do it before it is too late. 趁现在还不算太晚，你应该赶快做它。

2. 尚未来得及 Before she could move, she heard a loud noise, which grew to a terrible roar. 她还没有来得及动弹，就听见有很响的声音，接着就成了可怕的隆隆轰鸣声 Before they reached the house, a new great wave came, sweeping down trees, and sweeping them down too. 他们还没到屋子，又一个巨浪打来，冲倒了树，也冲倒了他们 3. 要 ......先...... You should be a pupil before you become a teacher. 要当老师，先作学生 二、掌握热点句型用法It was not long before...（过去）没过多久就...... It was not long before he returned to Beijing. 不久他就回到北京 需要特别注意，该句型可以进行创新，可将否定句改为肯定句（It was long before...过了很久才......）或将一般过去时改为一般将来时（It will not be long before...要不了多久就 ......；It will be long before...要过很久才......） 。

before 在这些句型中均引导时间状语从句， long 这个抽象的时间也可改为 years, weeks, days 等具体表时间的词 It was long before he married Wei Fang. 过了很久他才娶魏芳It will be long before he goes abroad. 要过很久他才出国 Will it be years before he goes to school? 要过好几年他才能上学吗？ 高考题例： It ________ long before we ________ the result of the experiment. A. will not be...will know B. is...will know C. will not be...know D. is...know 【析】正确答案为 C该句面意思为：在我们知道实验结果之前不会过很长一段时间，也就是不会过很长一段时间我们就会知道实验结果应使用 It was not long before 的创新句型 It will not be long before，before 引导时间状语从句时，从句应用一般现在时代替一般将来时。

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 【析】正确答案为 C该句型也是 It was not long before 的创新句型when 与 befor 的区别本文结合典型例题来归纳一下 before 的特殊用法before 作为连词时的基本意义是“在……之前”，用于表示时间或顺序如：Turn the light off before you sleep. (睡前先把灯熄掉) Think before you speak. (说话之前，应先想清楚) 但在不同的语境中 before 有不同的意义：1． before 表示“不等……就……”、 “尚未……就……” 例1： —Why didn’t you tell him about the meeting？ (2006年四川)—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。

题中 before 意为“ 不等……就”、 “尚未……就……” ，它表示从句的动作尚未来得及发生，主句的动作已发生或完成全句句意为：我还没来得及说他就冲出了房间又如：Before I could get in a word, he had measured me. 我还没有来得及插上话，他就给我量好了尺寸The phone stopped ringing before I answered it. 我还没有来得及接，就挂了2． before 表示“不知不觉，还没弄清就……”(常用于before sb. know／realize…)例2： Several weeks had gone by I realized the painting was missing. (2004全国)A. as B. before C. since D. when解析： 此题最易错选 C 或 D 项，而正确答案为 B用since 则时间延续到了现在，在时间上与 had gone 矛盾；用when 则无法强调时间流逝的不知不觉性又如：Time passed quickly and three months went by before I knew it. 时间飞快地流逝，不知不觉3个月过去了。

3． before 表示“以免，不然”例3： It’s cloudy. Take an umbrella you regret it.A. but B. and C. after D. before解析： and 及 but 表示并列关系，不合语境；after 意为“在……之后 ”，不合常识，应是在下雨前带伞；before 在此处意为“以免你后悔 ” before 作此意义的用法的例子不少，又如：Put that away before it gets broken. 把它收好，以免砸了Do it before you forget. 尽早动手，不然忘了4． before 用于 it was / will be ＋ 时间 ＋ before ... 句型中例4： It won’t be long you regret what you have done.A. after B. before C. since D. until解析： It was / will be ＋ 时间 ＋ before ... 表示“ 过了多久才…(强调时间的长) ”，在否定句中则表示“没过多久就…(强调时间的短 )”。

例如：It will be two years before we meet again.我们要过两年才能见面It wasn’t long before he married again. 不久他就又结婚了We didn’t wait long before he came back. 我们没等多久他就回来了5． before 表示“与其……宁可……，比……优先”(用于表优先顺序)例5： They would fight to death they surrendered(投降)．A. before B. after C. since D. because解析： 答案为 Abefore 引导的从句在与 will, would 连用时，有“宁愿……也不 ”的含义before 即使是作介词用也有此意义例如：True men choose death before dishonor. 大丈夫宁可杀不可辱I’d die before I apologize to them! 我宁死也不愿向他们道歉！We will die before we give in. 我们宁死不屈。

6. before 表示“……才” （强调从句动作发生得晚或慢）例6： They sailed along the Pacific Ocean for two weeks they arrived home.A. since B. when C. before D. after解析： 此题正确答案为 C全句句意为：“他们在太平洋航行了两个星期才回到家 ”强调从句动作比主句动作发生晚又如：I thought carefully about it before I made a decision. 我经过再三考虑才决定It may be many years before the situation improves. 或许要过很多年这种状况才能得到改善下面有一道2003年的高考题： Don’t be afraid of asking for help ____ it is needed.A. unless B. since 。