英语中时间状语从句
1、时间状语从句可由when，whenever，while，before，after，until，till，since，now that，once，as soon as等连词引起：Let’s wait until(till)the rain stops．
等雨停了再说。
She comes to talk to me whenever she feels lonely．
每当她感到寂寞时就来和我聊天。
As I talked，I gained some confidence．
我一面谈着一面增强了信心。
Now that I have come back,I want to help you both．
现在既然我回来了，我要帮助你们两人。
Once the train is moving，there is no way to stop it．
一旦火车开动了就没法址它停下来。
2、由every time，the moment等词引起的从句也可以用作状语
Every time I catch a cold，I have pain in my back
每回伤风我的背就疼。
Stormy applause broke forth the moment she appeared on the stage
她一在台上出现就响起暴风雨般的掌声。
He had impressed me that way the first time I met him．我第一次碰到他时，他就给我这个印象。
Be sure to call on us next time you come to town．
下次进城你一定来找我们。
3、instantly，immediately，directly等词也可引起时间状语从句
The machine will start instantly you press the button．
你一按电钮机器就会开动。
I’ll give you an answer immediately I’ve finished reading your report
我看完你的报告立即给你答复。
Directly he uttered these words there was a dead silence. 他一说出这些话，大家立刻沉默下来。
语法 29时间状语从句 一、什么是状语从句 状语就是在一句话中表示该句子的时间、地点、方式、原因、条件等成分。状语从句就是用一个从 句表示状语。状语从句根据它表达的意思不同，可分为时间、地点、原因、目的、结果、条件、方式、比较、让步等九类。 与状语一样，状语从句的位置比较灵活。既可置于主句之前（通常用逗号与主句隔开），也课置于主句之后（不需要用逗号与主句隔开），有时甚至可以置于主句之中。 二、时间状语从句 1. 主句和从句同时发生，这类从句由从属连词when, while, as引导。 He was hungry when he came home. I was crying while everyone was laughing. As I walked out, he walked in. as, when, while, 的区别 ① as强调从句的动作与主句动作同时发生及持续，具有at the same time的意思 他继续往下谈的时候，越来越兴奋。 as还可以表示一边??一边??，强调从句和主句中两个动作交替进行或同步进行。 他们边走边聊。 as还有“ 随着”的含义 随着春天的到来，天气暖和起来。 ② when 强调动作点的特定时间，具有at the time that 的意思 当老师走进来的时候，我们都站起来了。 ③ while 表示较长的期间，具有during the time that 的意思 当我在这的时候，我很安全。 2.主句发生在从句之前，这类从句由从属连词before, until 引导 ,before 意为“ 在---之前” until 在肯定句中意为“直到 --- 为止”，在否定句中意为“直到 --- 才”。从句既可置于主句前，也可置 于主句之后。 回家之前我必须干完所有的活。
条件句从句主句 真实一般现在时一般将来时 情态动词+动原祈使句 非真实 一般过去时 be动词用（were） would/could+动原初中英语――条件状语从句（讲解&练习） Ⅰ条件状语从句的定义 Ⅱ条件状语从句的引导词 1.if引导的条件状语从句：表示在某种条件下某事很可能发生。 If we pay much attention to the earth, we'll have a better world. 如果我们多关爱地球，就会拥有一个更美好的世界 If it rains tomorrow, what shall we do? 如果明天下雨，我们怎么办？ 注意：if还可以引导虚拟条件句，表示不可实现的条件，从句中多用一般过去时或过去完成时。 What would happen if there were no water ? 如果没有水会怎样？ 2.unless引导的条件状语从句，unless的意思是如果不，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引导的条件状语从句：as /so long as意思是“只要” So long as you're happy,i will be happy. 只要你高兴，我就高兴。 Ⅲ条件状语从句的种类 Ⅳ条件状语从句的时态原则 用法例句 ①主句为一般将来时态，if从句用一般 现在时态（即主将从现）。We will stay at home if it rains tomorrow. 如果明天下雨，我将要呆在家。 ②主句中含有情态动词，if从句用一 般现在时态。If you finish your homework, you can go home now.如果你做完了作业，你现在可以回家了。 ③主句为祈使句，if从句用一般现在 时态。Don’t jump into the river if you feel very hot. 如果你感到很热，不要跳入河里。 ④主句为过去将来时，if从句用一般 过去时态（如果涉及到be动词， 一律都用were）。此时，表达的是和现实相反的推测，用虚拟语 气。If I were you, I wouldn’t do it like that.如果我是你，我就不会那么做的。 If you gave me some money, I would be very happy. 如果你给我一些钱，我就会很高兴的。 二、if 引导的条件状语从句 （1）“if 从句+祈使句”的句子。其实，if 作为一个连词，主句也可以是其他形式的句子。 例如：If you want to go, please let me know. (2)“祈使句 + and (or)+ 陈述句”
初中英语状语从句知识点总结(一） 用来修饰主句中的动词，形容词或副词等而充当状语的从句叫做状语从句。状语从句常用从属连词来引导,与主句连接起来。若置于句末,则前面不加逗号。根据意义和作用，状语从句可分为时间原因条件等几种。下面我们就来分析一下这几种状语从句。 1时间状语从句 时间状语从句常用从属连词wheｎ,aｆtｅｒ，unｔil,as soon as，等来引导。 当主句是祈使句或谓语动词是一般将来时态或情态动词时,其时间状语从句中的谓语动词常用一般现在时态表示将来发生的动作或存在的状态。这就是我们常说的“主将从现”。 如:Ｐlease cａll me ｗheｎ yｏu ｇeｔｔｈere．当你到那时,请给我打个电话。 I ｗill write tｏ you ａs ｓｏｏn as I arrｉｖe in Beｉjing.我一到北京就给你写信。 <温馨提示>siｎce引导时间状语从句表示“自从…以来”，从句中的动词一般表示动作的起点，用过去时;而主句的动作延续的情况则用一般现在时或现在完成时。常用的句型为： It hａs beｅn/is+一段时间+ｓｉnｃe+过去时。 如：I hａs ｂeｅｎ/is three yeａrs since ｗe meｔ laｓt ｔｉｍe.自从我们上次见面,已经三年了。 2条件状语从句 引导条件状语从句的连词或词组有：if(如果),unless(除非),as ｌｏnｇ as(只要）等。如果主句是将来时，条件状语从句也用一般现在时来表示。 如：I will ｓtａy at home ｉf it raiｎs tomorrｏｗ.如果明天下雨,我就待在家。 You can’t learn Englisｈweｌl unｌess you woｒk ｈard． 除非你努力学习，否则是学不好英语的。 <温馨提示>由ｉf引导的条件状语从句，若从句表达的是与现在事实相反的事实,则常用虚拟语气,即用过去时态表示(如果涉及到ｂe动词，一律都用wｅre)。此时,主句则用过去将来时。
【英语】初中英语状语从句试题经典 一、初中英语状语从句 1． the journey was tiring，Jeff thought it was worth both the time and the money. A．As B．Since C．Unless D．Although 【答案】D 【解析】 【详解】 句意：虽然旅途很累，杰夫认为时间和金钱都值得。 A. As当……的时候； B. Since 自从； C. Unless除非； D. Although尽管。根据下文Jeff thought it was worth both the time and the money.可知上文是让步状语从句，这里用Although引导。根据题意，故选D。 2．-- Can’t I park my car free here? -- You can, for four hours, __________ you spend over 100 yuan in this supermarket. A．though B．if C．unless 【答案】B 【解析】 【详解】 句意：-我不能把车免费停在这里吗？- 如果你在这家超市花费超过100元，你可以免费停车四个小时。though 虽然；if 如果；unless 除非。这里是形容一种条件，如果消费超过100元，就能免费停车，故选B。 3．My English teacher has taught English she came to the school. A．since B．as C．when D．for 【答案】A 【解析】 【详解】 考查连词辨析，句意：我的英语老师自从来到这个学校就教英语．结合语境推断句意是"我的英语老师自从来到这个学校就教英语．"，此句中的谓语动词用了现在完成时，本题设空处后面的时间状语从句用了一般过去时，所以结合句意用现在完成时的标志词since引导，故选A 4．He made a serious mistake, but he took immediate action to change that ______ it got worse. A．until B．when C．because D．before 【答案】D 【解析】 试题分析：句意：他犯一个严重的错误。但他采取行动来改变它以免变得更糟。A. Until直到；B. When当……时；C. Because因为；D. Before在……之前。在变得更糟之前采取行动改
初中英语语法状语从句大全 1.时间状语从句 引导连词有when，while，till，not…until，since， after ,before ,as soon as The bus won’t start until everybody gets on. 公共汽车直到每人都上车为止，才开动。 When he knocked at the door I was cooking. 当他敲门时，我正在煮饭。 Last night before he came back home, his wife had already cooked dinner and waited for 2 hours. 昨天晚上在他回到家之前，他的妻子已经做好晚饭足足等了他两小时之久。 After I went to church, I went shopping. 2. 地点状语从句 地点状语从句通常由where, wherever 引导。 Where there is a will, there is a way. 哪里有志向，哪里就有出路。有志者事竟成。 Where there is a life, there is a hope. 哪里有生命，哪里就有希望。留得青山在，不怕没柴烧。 Wherever you go, whatever you do, I will be right here waiting for you. 不管你去哪里，不管你做什么，我都会在此守侯你。
3.原因状语从句 引导连词有because，as, since。 He didn′t see the film because he had seen it. 他没有看那部电影，因为他已经看过了。 They couldn’t get on the train，for it was too crowed. 比较：because, since, as和for 1) because语势，用来说明人所不知的原因，回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或 since。 I didn't go, because I was afraid. Since /As the weather is so bad, we have to delay our journey. 2) 由because引导的从句如果放在句末，且前面有逗号，则能 够用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。 He is absent today, because / for he is ill. He must be ill, for he is absent today.
时间状语从句常由以下连接词引导：when（当……时），as（一边……一边；当…时），while（在……期间），after（在……之后），before（在……之前），as soon as（一……就），since（自从），till(until)（直到……，直到……才），whenever（任何时候），the moment（一……就），no sooner than（一……就），hardly…when… （一……就）等。由以上连接词（或词组）连接的主从复合句中，主句和从句的动作，有的是同时发生，有的是先后发生。因此，要特别注意根据连接词所代表的时间不同，主句和从句的谓语要使用相应的时态。这是掌握时间状语从句的关键。 1. when 和whenever 引导的从句：从句的动作和主句的动作可以同时发生，也可以先于主句的动作发生。例如： When we reached home, it was already dark. 我们到家的时候天已经黑了。 When my cousin came yesterday, I was playing volleyball. 昨天我表哥来时，我正在打排球。 When it rains, I go to school by bus.下雨的时候，我坐车去学校。 I shall tell her the good news when she comes. 她来时，我将告诉她这个好消息。（主从句都表示将来发生的动作，但要注意从句中要用一般现在时，表示将来。） Come to see us whenever you can.你什么时候有空，就过来看看我们。 2. while 和as 引导的从句：while表示“当…过程中”，强调某一段时间主句和从句的动作在同时发生。as表示“当…时”或 “一边…一边”，主句和从句的动作同时发生。例如： Work while you work; play while you play. 该工作的时候就工作，该玩的时候就玩。 While he is reading, he always makes notes. 他经常一面看书，一面做笔记。 She sings as she goes along.她边走边唱。 You will grow wiser as you grow older. 随着年龄的增长，你会更加聪明起来。 3. before 和after 引导的从句：前者一般表示主句的动作发生在从句动作之前。后者表示主句的动作发生在从句动作之后。 例如： I didn’t know any English before I came here. 我来这儿之前，一点英语都不懂。 I had written my report before my mother came back.
状语从句 什么是状语： 句子中修饰动词、形容词等的句子成分叫状语，用来从地点、时间、原因、目的、结果、条件、让步、比较、方式和伴随状况等方面修饰说明谓语。 e.g. He speaks English very well.（副词作状语） e.g. He is playing under the tree.（介词短语作状语） e.g. I come specially to see you.（不定式作状语） e.g. If I am not busy tomorrow,I will play football with you.（从句作状语） e.g. Having had a quarrel with his wife,he left home in a bad temper.（分词作状语） 状语从句： 状语从句就是在复合句里起状语作用的从句，可以表示时间、地点、原因、目的、结果、让步、比较、方式、条件等。引导状语从句的连词叫做从属连词。状语从句的位置可以在句首，也可以在句末。放在句首时，从句后面常用逗号与主句隔开；放在句末时，从句前面往往不用逗号。 If it’s fine tomorrow, I wil l go with you. I will go with you if it’s fine tomorrow. 状语从句分类：1、时间状语从句 2、地点状语从句 3、原因状语从句 4、目的状语从句 5、结果状语从句 6、条件状语从句 7、让步状语从句 8、比较状语从句 9、方式状语从句 时间状语从句 从属连词：when, while, as, before, after, till/until, since, whenever, as soon as（一……就）…… 时态：主将从现，主情从现，主祈从现 一、When/while/as（当…时候）
状语从句 一. 单项填空 1. _______ he’s old, he can still carry this heavy bag. A. Though B. Since C. For D. So 2. ---Do you know if he _______ to play basket ball with us? ---I think he will come if he ______ free tomorrow. A. comes; is B. comes; will be C. will come; is D. will come; will be 3. In the zoo if a child _____ into the water and can’t swim, the dolphins may come up ______ him. A. will fall; to help B. falls; to help C. will fall; help D. falls; helping 4. I don’t remember ________ he worked in that city when he was young. A. what B. which C. where D. who 5. We will stay at home if my aunt ________ to visit us tomorrow. A. comes B. come C. will come D. is coming 6. The police asked the children _______ cross the street ________ the traffic lights turned green. A. not; before B. don’t; when C. not to; until D. not; after 7. I was late for class yesterday _______ there was something wrong with my bike. A. when B. that C. until D. because 8. I’ll go swimming with you if I ________ free tomorrow. A. will be B. shall be C. am D. was 9. In the exam, the ________ you are, ______ the _______ mistakes you will make. A. careful; little B. more careful; fewest C. more careful; fewer D. more careful; less 10. Y ou should finish your lessons _______ you go out to play. A. before B. after C. when D. while 11. I hurried _____ I wouldn’t be late for class. A. since B. so that C. as if D. unless 12. When you read the book, you’d better make a mark _______ you hav e any questions. A. which B. that C. where D. though 13. The teacher raised his voice _______ all the students could hear him. A. for B. so that C. because D. in order 14. He took off his coat _______ he felt hot. A. because B. as C. if D. since 15. It is ______ that we’d like to go out for a walk. A. a lovely day B. too lovely a day C. so lovely a day D. such lovely a day 16. Mary had ______ much work to do that she stayed at her office all day. A. such B. so C. too D. very 17. _______ I felt very tired, I tried to finish the work. A. Although B. Because C. As D. As if 18. ______ the day went on, the weather got worse. A. With B. Since C. While D. As
初中英语语法状语从句专练及答案 1 ( ) 1 The meeting didn't start___ everyone was there. A. because B. until C. why D. if ( ) 2 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 ( ) 3 I won't believe you___ I have seen it with my own eyes. A. before B. until C. after D. when ( ) 4 He ___ home ___ she was satisfied ___ his answer yesterday. A. didn't go; until; with B. wasn't go; after; to C. doesn't go; before; with D. didn't go; until; to ( ) 5 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 ( ) 6 They didn't start the work ___ their teacher came back. A. until B. while C. as soon as D. if 2 ( ) 1 Tom will call me as soon as he ___ Shanghai. A. arrives B. will reach C. arrives in D. get to ( ) 2 I'm sure he'll come to see me before he ___ Beijing. A. will leave B. is leaving C. leave D. leaves ( ) 3 I will tell him the news as soon as he___ back. A. come B. comes C. will come D. came 3 ( ) 1 Tom has got a watch. He ___ it for two years. It _______ by his father. A. has bought; was bought B. has got; is bought , C. was bought; has bought . D. has had; was bought "' ( ) 2 When he got to the station, the train ___. A. left B. had left C. leaves D. has left ( ) 3 The boy told his father what he ___ in the street. A. saw B. have seen C. had seen D. see ( ) 4 We ___ TV when the telephone ____. A. watched; was ringing B. were watching; rang C. watch; rings D. are watching; rang ( ) 5 By the end of last term, I___ ten books. A. had finished reading B. have finish reading
要注意主句和从句的时态大多都要保持一致。） 1.由when, while, ,just ,just as, as，after, before, since, until, as soon as,引导的时间状语从句。例如： When you think you know nothing, then you begin to know something. 当你以为自己一无所知的时候，你就是在开始知道一些事物了。 When truth is buried under the ground ，it grows, it chokes, it gathers such an explosive force that on the day it bursts out , it blows up everything with it. 当真理被埋在地下的时候，它在生长，它感到压抑，它蓄存着这么一种爆炸性力量，一旦冒出，它就会炸破一切！ Strike while the iron is hot. 趁热打铁。 You can feel the air moving as your hand pushes through it. 当你的手在空气中挥动的时候，你就能感觉到空气在流动。 Our headmaster laughed as she spoke. 我们的校长边谈边笑。 主要时态：主现从不现；主过从四过；主将从现。 when, while和as的区别 when引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词；动作既可以 和主句的动作同时发生，又可以在主句的动作前后发生。并且when有时表示“就在 那时”。 例如： When she came in, I stopped eating.她进来时，我停止吃饭。(瞬时动词) When I lived in the countryside, I used to carry some water for him. 当我住在农村时，我常常为他担水。（延续性的动词） We were about to leave when he came in.我们就要离开，就在那时他进来了。While引导的从句的谓语动作必须是延续性的，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。 例如： While my wife was reading the newspaper, I was watching TV. (was reading是延续性的动词，was reading和was watching同时发生) 。 I like playing football while you like playing basketball. 我喜欢踢足球，而你喜欢打篮球。（对比） As表示“一边……一边”，as引导的动作是延续性的动作，一般用于主句和从句动 作同时发生；as也可以强调“一先一后。例如： We always sing as we walk.我们总是边走边唱。（as表示“一边……一边”）As we were going out, it began to snow.当我们出门时，开始下雪了。 （as强调句中两个动作紧接着先后发生，而不强调开始下雪的特定时间）
初中英语语法状语从句讲解专项练习选择合适的连接词，完成下列句子。 spends a lot of money on books______he is not rich. fell into sleep ______she was listening to the music. David at school today ----No. He is at home ______he has a bad cold. , won't have supper ______my mother comes back. to him slowly ______he may understand you better. 6. ______ she doesn't come on Sunday, I'll go fishing by myself. is four years ______I had left that small village. 8. ______the air moves, it is called wind. will go to the park ______it doesn't rain tomorrow. boys did ______much work. are few new words in the passage ______we can't understand it. ? back ______you come from. reached the station ______the train had left. you have a swimming pool ----No, we don't. At least, not ______big ______yours. me your paper ______you have finished it. is raining hard, ______we have to stay at home. 17. ______you work harder, you'll never pass the final exam. after the children ______I am out. ' village is ______far away ______I can't get there on foot. is ______an interesting book ______I can't stop reading it. 能力提高练习 1 ( ) 1 The meeting didn't start___ everyone was there. A. because B. until C. why D. if ( ) 2 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 ( ) 3 I won't believe you___ I have seen it with my own eyes. A. before B. until C. after D. when ( ) 4 He ___ home ___ she was satisfied ___ his answer yesterday. A. didn't go; until; with B. wasn't go; after; to C. doesn't go; before; with D. didn't go; until; to ( ) 5 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 ( ) 6 They didn't start the work ___ their teacher came back. A. until B. while C. as soon as D. if 2 ( ) 1 Tom will call me as soon as he ___ Shanghai. A. arrives B. will reach C. arrives in D. get to ( ) 2 I'm sure he'll come to see me before he ___ Beijing. A. will leave B. is leaving C. leave D. leaves ( ) 3 I will tell him the news as soon as he___ back. A. come B. comes C. will come D. came 3 ( ) 1 Tom has got a watch. He ___ it for two years. It _______ by his father. A. has bought; was bought B. has got; is bought , C. was bought; has bought . D. has had; was bought "' ( ) 2 When he got to the station, the train ___. A. left B. had left C. leaves D. has left
[编辑本段] 简介 （adverbial clause of time） 概念：在复合句中，由时间连接词引导的状语从句叫做时间状语从句。(在复合句中，要注意主句和从句的时态大多都要保持一致。） 时间状语从句 1.由when, while, as，after,before,since,untill,引导的时间状语从句。例如： When you think you know nothing, then you begin to know something. 当你以为自己一无所知的时候，你就是在开始知道一些事物了。 When truth is buried under the ground it grows, it chokes, it gathers su ch an explosive force that on the day it bursts out , it blows up everything with it.当真理被埋在地下的时候，它在生长，它感到压抑，它蓄存着这么一种爆炸性力量，一旦冒出，它就会炸破一切！ Strike while the iron is hot. 趁热打铁。 You can feel the air moving as your hand pushes through it. 当你的手在空气中挥动的时候，你就能感觉到空气在流动。 Our headmaster laughed as she spoke.我们的校长边谈边笑。 主要时态：主过从过；主将从现；主句为一般现在时，从句不受影响。 [编辑本段] 区别 when, while和as的区别：when引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。并且when有时表示“就在那时”。例如：
初中英语状语从句 【考点直击】 1. 时间状语从句 2. 条件状语从句 3. 原因状语从句 4. 结果状语从句 5. 比较状语从句 6. 目的状语从句 7. 让步状语从句 8. 地点状语从句 【名师点睛】 用来修饰主句中的动词，副词和形容词的从句叫状语从句。根据其含义状语从句可分为时间状语从句，地点状语从句，条件状语从句，原因状语从句，结果状语从句，比较状语从句，目的状语从句，让步状语从句。 1. 时间状语从句 (1)时间状语从句常用when, as, while, before, after, since, till, until, as soon as等连词来引导。例如： It was raining hard when got to school yesterday. While he was doing his homework, the telephone rang. As he walked along the lake, he sang happily. He had learned a little Chinese before he came to China. After he finished middle school, he went to work in a factory. (2)在时间状语从句里，通常不用将来时态，用现在时态表示将来的动作或状态。例如： I’ll ring you up as soon as I get to New York. I will tell him everything when he comes back. He won’t believe it until he sees it with his own eyes. (3)在带有till或until引导的时间状语从句的主从复合句里，如果主句用肯定式，其含义是“一直到……时”，谓语动词只能用延续性动词。如果主句用否定式，其含义是“直到……才……”, “在……以前不……”, 谓语动词可用瞬间动词。例如：The young man read till the light went out. Let’s wait until the rain stops. We won’t start until Bob comes. Don’t get off until the bus stops. 2. 条件状语从句 (1)条件状语从句通常由if, unless引导。例如： What shall we do if it snows tomorrow? Don’t lea ve the building unless I tell you to. (2)在条件状语从句里，谓语动词通常用现在时态表示将来的动作或状态。例如： I’ll help you with your English if am free tomorrow. He won’t be late unless he is ill. (3)“祈使句+ and (or)+ 陈述句”在意思上相当于一个带有条件状语从句的复合句。例如： Hurry up, or you’ll be late. =If you don’t hurry up, you’ll be late. Study hard and you will pass the exam. =If you study hard, you will pass the exam. 3. 原因状语从句 (1)原因状语从句通常由because, since, as引导。例如： He didn’t come to school because he was ill. As it is raining, we shall not go the zoo. Since you can’t answer the question, I’ll ask someone else. (2)because表示直接原因，语气最强。Because引导的原因状语从句多放在主句之后。回答由why提出的问题，只能用because。
状语从句 状语从句用来修饰主句中的动词，副词和形容词的从句叫状语从句。根据其含义状语从句可分为时间状语从句，地点状语从句，条件状语从句，原因状语从句，结果状语从句，比较状语从句，目的状语从句，让步状语从句。 1. 时间状语从句 (1)时间状语从句常用when, as, while, before, after, since, till, until, as soon as等连词来引导。例如： When while as 的区别It was raining hard（rain hard 下大雨）when got to school yesterday. While he was doing his homework, the telephone rang. As he walked along（沿着走）the lake, he sang happily. He had learned a little Chinese before he came to China. After he finished middle school, he went to work in a factory. (2)在时间状语从句里，通常不用将来时态，用现在时态表示将来的动作或状态。例如： I’ll ring you up as soon as I get to New York. I will tell him everything when he comes back. He won’t believe it until he sees it with his own eyes. (3)在带有till或until引导的时间状语从句的主从复合句里 如果主句用肯定式，其含义是“一直到……时”，谓语动词只能用延续性动词。 如果主句用否定式，其含义是“直到……才……”, “在……以前不……”, 谓语动词可用瞬间动词。 例如： The young man read till the light went out（熄灭）. Let’s wait until the rain stops. We won’t start until Bob comes. Don’t get off（从下来）until the bus stops. 【。固定组合里from morning till night，till/until是不能替换的，】 2. 条件状语从句 (1)条件状语从句通常由if, unless引导。例如： What shall we do if it snows tomorrow? Don’t leave the building unless I tell you to. (2)在条件状语从句里，谓语动词通常用现在时态表示将来的动作或状态。例如： I’ll help you with your English if am free tomorrow. He won’t be late unless he is ill. (3)“祈使句+ and (or)+ 陈述句” 在意思上相当于一个带有条件状语从句的复合句。例如： Hurry up, or you’ll be late. =If you don’t hurry up, you’ll be late. Study hard and you will pass the exam. =If you study hard, you will pass the exam. 3. 原因状语从句 (1)原因状语从句通常由because, since, as引导。例如： He didn’t come to school because he was ill. As it is raining, we shall not （不得；不应该）go the zoo. Since you can’t answer the question, I’ll ask someone else.