时间状语从句 一、概述 概念：在复合句中，由时间连接词引导的表示时间的从句叫做时间状语从句。　　 一般来说，时间状语从句常由连词 when,while, as, before, after, as soon as 或 until,since 等引导。 注意：如从句表将来时，采用“主将从现”原则。 eg. I will go to the cinema as soon as I finish my homework. When I grow up, I will join the army. 二、引导词的用法与辨析 (1) when 引导的谓语动词可以是延续性的动词，也可瞬间性动词。 eg When she came in, I stopped eating. ( ) ： 瞬 间 性 动 词 When I lived in the countryside, I used to carry some water for him. （ 延 续 性 动 词 ） (2) while 引 导 的 动 词 必 须 是 延 续 性 的 ， 并 强 调 主 句 和 从 句 的 动 作 同 时 发 生 （ 或 者 相 对 应 ） . 　 并且 while 有时还可以表示对比。 e.g：While my wife was reading the newspaper, I was watching TV. （3）until 引导肯定句时，谓语需用延续性动词，意为“直到….”； 引导否定句时，谓语动词是延续性或瞬间性动词，意为“直到….才….” eg. He waited until all the people 　　 I didn't go to bed until Mum came back.　 left. 　 （ 4 ） as soon as 表 示 “ 一 … … 就 … … ” ， 强 调 动 作 紧 密 相 连 。 如 ： 　　We start to sing as soon as it is 12 o’clock. 　　We began to work as soon as we got there.　 （5）由 before 和 after 引导的时间状语从句。 be four days before they come back. 他 们 要 过 四 天 才 能 回 来 。 　　Einstein almost knocked me down before he saw me. 爱因斯坦几乎把我撞倒才看到我。 After you think it over, please let me know what you decide.　你仔细考虑过以后，告诉我你是怎样决定的。 It will 三、专题过关练习 （一）单项选择 （ ）1. Hurry up, Jack. We have to get to the station _______11:45 so that we can catch the 12:00 train. A. since B. after C. before D. until （ ）2. ______ they drive any of the buses, they will have to pass a special test. A. Before B. After C. When D. While （ ）3. The foreigners ________ arrive ________ yesterday. A. won’t …until B. didn’t …until C. not … until D. didn’t …since （ ）4. _______ you lose it, you can’t get it back. A. Once B. Because C. While D. Until （ ）5. ______ Mrs. Wilson came into the classroom, all the children welcomed her. A. Before B. After C. As soon as D. Until ( ) 6. The meeting didn't start___ everyone was there. A. because B. until C. why D. if ( ) 7. The boy ___ to bed ___ his mother came in. A. went not; until B. didn't go; after C. went; until D. didn't go; until ( ) 8. I won't believe you___ I have seen it with my own eyes. A. Before B. unless C. After D. When ( ) 9. I ___ him since I began to live in the city. A. know B. have known C. knew D. will know ( ) 10. He ___ back until the work ___ done. A. isn't; will be B. isn't; is C. won't be; will be D. won't be; is (二) 完成句子。 1. 你一到广州就给我打个电话好吗？ Will you please call me ______ ______ ______ you get to Guangzhou？ 2. 他长大后想当一名医生。 He wants to be a doctor ______ _______ _______ _______. 3. 我哥哥昨晚直到 12 点才睡觉。 My brother _________ go to bed ________ 12 o’clock last night. 4. 请在校门口等到你哥哥来。 Please for your brother at the school gate 5. 过马路前你要先看两边。 Watch the two ways he . across the road. 条件状语从句 一、概述 在句子中做条件状语的从句称为条件状语从句。可置于句首、句尾，有时还可置于主语和谓语之间。引导条 件状语从句的连接词有：if , unless, as/so long as，once 等 二、引导词极其用法 1.if “如果” If it rains tomorrow, what shall we do? 如果明天下雨，我们怎么办？ 注意 ：顺口溜 if 条件句不一般,几个要点记心间; 条件句,放在前,逗号要放句中间。 条件句表可能，主句多用将来时； 条件句表事实，主句常用现在时。  注意：如从句要表可能要发生的事，采用“主将从现” eg. If it rains tomorrow ,we will not go to the zoo. 如果 if 条件句谈论的是重复发生和预示要发生的情景和事件，一般主从句都用一般现在时。如： If bears are in danger , they attack people.  2.unless “如果不，除非”，可与 if...not 互换。 You will fail in English unless you work hard. 你英语考试会不及格的，除非你更加努力。 3.as /so long as “只要” 只要你高兴，我就高兴。 So long as you're happy, I will be happy. 4.once “一旦...，就”，从句可置于主句前或后。 Once you begin, don’t stop. 一旦开始，就不要停止 Maths is easy to learn once you understand the rules. 一旦你理解了规则，数学就不难学了。 注意：在条件状语从句中，用一般现在时代替一般将来时，用一般过去时代替过去将来时。 If the weather is bad next week, we'll put off the climbing. 如果下周天气不好，我们将推迟爬山。 Father told me if I worked hard he would buy me a gift. 爸爸告诉我，如果我努力学习，他会给我买一份礼物。 三、过关练习 （一）单项选择 ( ) 1.If you _____ to the party, you’ll have a great time. A. will go B. went C. go D. going ( ) 2. It will be a long time ____ Peter _____ his work. He always does things slowly. A. since, has finished B. after, finishes C. when, will finish D. before, finishes. ( ) 3. What will father _____ us when he _____ back from Japan? A. take , come B. bring , come C. takes, comes D. brings, comes ( ) 4. Guangzhou _______more beautiful, if we ______ more trees. A. will be, plant B. is, plant ( ) 5. I ___ _ her the answer if she __ A. can tell, will ask C. will be, plants D. is, plants __me. B. will tell, will ask C. would tell, ask D. will tell, asks ( ) 6. – What are you going to do tomorrow? --We’ll go to the library tomorrow if it __ A. isn’t rain B. rain _. C. won’t rain D. doesn’t rain ( ) 7.—Do you