because because of since 练习

状语从句一、状语从句的定义状语从句（Adverbial Clause）是指句子用作状语时，起副词作用的句子。

状语从句可以修饰谓语、非谓语动词、定语、状语或整个句子。

状语从句根据其作用可分为：时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。

状语从句一般由连词（从属连词）引导，也可以由词组引起。

从句位于句首或句中时通常用逗号与主句隔开，位于句尾时可以不用逗号隔开。

二、状语从句常用引导词1. 时间状语从句as /while /whe n /un til /once /since / before; whe never, he first/last time,every/each time等。

2. 地点状语从句3. 原因状语从句4. 条件状语从句5. 目的状语从句6. 结果状语从句7. 方式状语从句where/wherever 等。

because/as/si nce/fo 等。

if/unl ess/as long as 等。

so that/i n order that/i n case等。

so...that/such...that/so tha等。

as/as if(though)等。

than/as …as/the more …the 等ore9. 让步状语从句although/no matter+.../eve n if/ whatever/ as尽管）等。

三、状语从句分析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 ( rain hard 下大雨) when got to school yesterday.While he was doing his homework, the teleph one rang.As he walked along (沿着走)the lake, he sang happily.(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。

（英语）中考英语连词技巧和方法完整版及练习题一、初中英语连词1．I've wanted to read Peter Pan for long, _________ today I finally borrowed the book from the library.A. orB. butC. andD. since 【答案】 C【解析】【分析】句意：我一直想读《彼得潘》，今天我终于从图书馆借到了这本书。

A 或者、否则；B但是，C和；D自从，句子前后是并列关系，则应用连词and，故选C。

【点评】此题考查联系辨析。

根据两句之间的关系确定所使用的连词。

2．——What do you think of our school basketball team?——They're going to lose the match __________ they improve their skills.A. unlessB. untilC. ifD. as【答案】 A3．Some people won't realize the importance of their health ____ they lose it.A. becauseB. afterC. whenD. until【答案】 D4．Although she is under great stress, ______ she always wears a smile on her face.A. andB. orC. butD. /【答案】 D5．_____________ my brother arrived in Thailand, he visited the local biggest temple at once.A. As soon asB. WhileC. UntilD. Before 【答案】 A6．British people and Australian people speak the same language, ______________ they have different customs and cultures.A. andB. butC. soD. for【答案】 B7．Tom's father was cleaning the car _______________ his mother was doing housework. A. although B. as C. since D. while 【答案】 D8．__________ the teacher came in, the students stopped reading at once.A. WhenB. WhileC. BeforeD. /【答案】 A9．Jim has been in the factory for two months ________ he left school.A. whenB. sinceC. as soon asD. whether 【答案】 B10．Yesterday morning I was just leaving the telephone rang.A. whenB. whileC. becauseD. since 【答案】 A11．Your dream will come true ______________ you put your heart and soul into it.A. ifB. unlessC. althoughD. until【答案】 A【解析】【分析】句意：如果你全心全意，那么你的梦想将会实现。

状语从句讲解与练习一、时间状语从句定义：用从句来表达一件事情或一个行为发生的时间(一) before & afterbefore：“在……之前”，主句动作发生在从句动作之前[主前从后]after：“在……之后”，主句动作发生在从句动作之后[主后从前]He called me after he finished his homework.He had learned English for three years before he went to London.(二)as soon as 一……就…… [主将从现]表示从句动作一发生，主句动作马上就发生。

I'll tell her everything as soon as she comes back.As soon as I reached Canada, I rang him up.(三) since 自从(1) 主句【现在完成时】+ since时间状语从句【一般过去时】He has gone abroad since he was 20.(2) It’s + 一段时间+ since时间状语从句【一般过去时】It is 10 years since we became friends.(四) until(1) 用于肯定句中，表示主句的动作一直持续到从句动作发生或状态出现时为止。

一般可译为“直到……为止”。

主句的动词必须是延续性的。

He will stay here until his mother comes back. [主将从现](2) until用于否定句中，表示主句的动作在从句的动作发生之后才开始。

一般可译为“直到……才……”或“直到……之前不要……” 。

主句的动词多为非延续性。

Don”t get off the bus until it has stopped.The little girl didn’t stop crying until she saw her mom.(五) when & while & as(1) 理论基础①三者都可表示“当……时”② while只接持续性动词，when/as持续、短暂都可以接③while 多用于进行时态，when多用于一般时态(2) 一般时while进行；进行when一般时The telephone rang while I was taking a bath.I was reading a newspaper when he came in.(3) 事件对比用while（然而；却）Father was preparing a report while I was playing PC games.He likes coffee while she likes tea.(4) “随着”/“一边…一边”用asThings are getting better and better as time goes on.She sang as she went along.二、原因状语从句because 因为（不与so连用）(1) because &because ofbecause引导原因状语从句because of 是介词短语，后跟n./pron./V-ing，句中作原因状语-- Why didn't he come here?-- He didn’t come here because he was ill.-- He didn’t come here because of his illness.(2) because & for & since & asbecause 语气最强烈；for放句中，用来表示一种附带或补充解释、说明；since & as 通常放句首，作“既然”讲。

比较Because，Since，As和For的用法英语中常用介词Because，since，as 和for 表示原因和理由,但它们的用法又不尽相同，有的表直接原因，有的表间接原因。

它们有语气的不同，在句中的位置也有区别。

学习中要注意把握区别，正确使用。

本文现对Because，since，as and for的用法和比较作以下分析。

请看下面的几个句子：1.Please drop in often，for we are always eager to see you.（请常来坐坐，我们总是热望见到你。

）2.Since force is no remedy，let us try conciliation.（既然武力无济于事，让我们试试和谈吧。

）3.As it is going to rain, let’s stop working.（因为要下雨了，我们停止工作吧。

）4.I know Mr. Green didn’t go with them, because I saw him just now.（我知道戈林先生没有和他们一道去，因为我刚才看见他。

）二虽说because，since，as 和for 都能表达理由和原因，但它们之间是有区别的：第一，强调表达直接原因多用because表达。

Because一词特别强调理由和原因；而且，由它所连接的从句多半放在主句之后来进行解释。

例如：1.That youth has been praised because he works hard without complaint.（那位青年被表扬，因为他工作努力毫无怨言。

）2.I did it because I thought it would help you so much.(我做这事是因为我认为它会对你有很大帮助的。

)第二，如果表达的原因、理由是显而易见的，多用for 这个连词。

For 所表达的“因为”这一概念，不如because 强烈，且在口语中已不常用。

（英语）英语连词的基本方法技巧及练习题及练习题(含答案)及解析一、初中英语连词1．The teacher got angry _________________ what we had done in class yesterday.A. becauseB. because ofC. asD. but【答案】 B【解析】【分析】句意：老师因为我们昨天在课堂上做的事情感到生气。

A因为，引导原因状语从句，B因为，引导名词从句，C由于，引导原因状语从句，D但是，what we had done in class yesterday是名词从句，故用because of引导，故选B。

【点评】考查代词辨析，注意because of的用法。

2．____it rained a lot, we enjoyed our holiday.A. AlthoughB. BecauseC. UnlessD. However【答案】 A3．Some people won't realize the importance of their health ____ they lose it.A. becauseB. afterC. whenD. until【答案】 D4．You will find it useful to learn to study by yourself _____ you go to college.A. whileB. untilC. SinceD. when【答案】 D5．_____________ my brother arrived in Thailand, he visited the local biggest temple at once.A. As soon asB. WhileC. UntilD. Before【答案】 A6．The situation is becoming more serious ________________ we do something to save the Earth.A. ifB. whenC. becauseD. unless【答案】 D7．__________ the teacher came in, the students stopped reading at once.A. WhenB. WhileC. BeforeD. /【答案】 A8．You can take___________ the train___________ the bus there. It will take the same amountof time.A. eithers orB. both andC. neither; norD. not only: but also【答案】 A9．Little Kate went to school___________ it rained heavily yesterday.A. thoughB. ifC. butD. since【答案】 A10．Some people waste food___________ others haven't enough.A. whileB. duringC. whenD. which【答案】 A11．A recent survey shows that 44 percent of Americans want to use self-driving cars,_________ 34 percent believe that they will make the roads mote dangerous.A. althoughB. becauseC. if【答案】 A【解析】【分析】句意：一个近来的调查显示44%的美国人想要使用无人驾驶车，尽管34%的人相信它们会让道路更加危险。

连词练习题 （含答案 ）一、初中英语连词1． I got up at six this morning ___________ I could catch the early bus to Nanjing.A. soB. thatC. in order toD. so that【答案】 D点评】考查连词辨析。

注意句子涉及到祈使句， and/or+ 陈述句的用法。

4． ___________ she is a very busy woman, she helps the boy.A. AlthoughB. Because C . However D . But【答案】 A【解析】 【分析】句意：虽然她是个很忙的女人，但是她帮助那个男孩。

A ： Although ，虽 然，表示转折关系。

B ： Because ，因为，表示因果关系。

C ： However ，然而，表示转折。

D ： But ，但是，表示转折。

根据 ____________ she is a very busy woman, she helps the boy. 可知，她是个很忙的女人和她帮助那个男孩是转折关系，但用在第一个句子前，只能是 although ，故选 A 。

【点评】考查连词辨析。

注意连词的意思和区别，结合句意，选出正确答案。

5． ___________ China has been a member of WTO, English is more important.A. SinceB. ThoughC. WhenD. If【答案】 A【解析】 【分析】句意：自从中国加入 WTO 后，英语就更重要了。

since 自从， though 虽 然； when 当 ⋯⋯时候； if 如果，只有 since 是正确的， though 放在此处句子翻译不通顺； when 不和现在完成时连用； if 引导从句是一般现在时或现在完成时，主句用将来时，故选 A 。

高中英语原因状语从句形式单选题40题1.She was absent from school yesterday because she was ill.A.because she was illB.because she had a meetingC.because she went shoppingD.because she visited her grandparents答案：A。

本题考查because 引导的原因状语从句。

A 选项中“because she was ill”表示因为她生病了，符合前面说的她昨天没去上学的原因。

B 选项她有个会议不是她没去上学的原因；C 选项她去购物也不是没去上学的理由；D 选项她去看望祖父母同样不是缺课的原因。

2.He didn't go to the party because he had to study for the exam.A.because he had to study for the examB.because he wanted to watch TVC.because he was tiredD.because he had a headache答案：A。

“because he had to study for the exam”因为他得为考试学习，这是他没去参加聚会的合理原因。

B 选项想看电视不是不去聚会的主要原因；C 选项累了也不是主要原因；D 选项头疼也不太符合不去聚会而选择学习这个场景。

3.We stayed at home because it was raining.A.because it was rainingB.because we were boredC.because we had no moneyD.because we wanted to sleep答案：A。

“because it was raining”因为下雨，所以我们待在家里，逻辑合理。

英语重点词汇辨析because,because of,since,as forbecause,because of,since,as,for这几个词都可以表示“原因”，语气由强至弱依次为：because(because of)→since→as→for.首先分别了解一下他们:1. Because释义：conj.因为。

表示直接原因，其语气最强。

常用来回答why的提问，一般放于主句之后，也可以单独存在。

because是从属连词，后接原因状语从句。

because不能与so连用。

理解重点：直接原因、回答why、强调句型例句:Because it was raining, we stayed at home.因为下雨，所以我们得呆在家里。

Why you choose this sport?你为什么选择这项运动？He left because he didn't want to be tagged as a soap star.他之所以离开是因为他不想被人称作是肥皂剧明星。

2.Because of释义:conj.因为，由于（说明）表示直接原因，其语气最强。

because of是个介词短语，不可以引导原因状语从句，而应该接名词、代词、动词的ing形式或者名词性从句等。

理解重点：直接原因例句:Because of my country accent, people identified me with a homely farmer's wife.由于我的乡下口音，人们将我等同于平常的农妇。

The team might be seeded because of their pull within soccer's international body.凭其在国际足球机构的影响力，该队有可能被定为种子队。

Many quite reasonable people were at panic stations because of popular unrest.许多相当理智的人由于普遍的不安情绪也处于紧张状态。

Unit 7 The unknown world 语法练习一．基础巩固。

( )1. I hate travelling by air_____ you usually have to wait for hours before the plane takes off. A. because B. though C. until D. Unless( )2. Because it is hot, _____ we decide to go swimming.--Can I join you?A. soB. thusC./D. for( )3.—Why you are absent?--_____ I am ill.A. SinceB. ForC. AsD. Because( )4.____ everyone is here, let’s begin.A. ButB. SinceC. SoD. If( )5.She was praised______ she often helped others.A. butB. forC. orD. if( )6.______ the heavy snow, we didn’t go to school.A. BecauseB. Because ofC. ForD. Since( )7.Because it is raining,_____ we have to put off the sports meeting.A. soB./C. andD. then( )8.--_______it is late , I should go home now.--Oh, do you have to?A. SinceB. OrC. Because ofD. But( )9.—The sun must have set,____ it is growing dark.--- Yes, and it’s 6 o’clock now.A. forB./C. howeverD. thus( )10.--- I will go to the party alone ____ you don’t want to go.A. untilB. sinceC. howeverD. whether( )12. The man can’t get on the bus ______ there is no room on it.A. thoughB. becauseC. until D so that( )13. ______ her daughter hadn’t come back, ______ she looked worried.A. Because, /B. Because, soC. Though, butD. Though, /( )14._______ you’ve got a chance, you might make full use of it.A. Now thatB. AfterC. AlthoughD. As soon as( )15. He found it difficult to read, _______ his eyesight was beginning to fail. A. and B. for C. but D. or( )16. A man cannot smile like a child, ________ a child smiles with his eyes, while a man smiles with his lips alone. A. so B. but C. and D. For形容词、副词综合复习与训练( )1．Water is the cheapest drink. And it's also ________.A．healthier B．healthiest C．the healthier D．the healthiest ( )2．—How do you feel about the movie？—Wonderful！I've never seen a __B__ one before.A．good B．better C．best( )3.It is ____ to do things well than do big things poorly.A．worse B．funnier C．better( )4. There are many beautiful flowers in the world, but in parents' eyes, their children are the ____ of all.A．as beautiful as B．more beautiful C．most beautiful( )5．This movie wasn't ____．He fell asleep half way through it.A. interesting enoughB. enough interestingC. interested enoughD. enough interested( )6．—I think English is as ____ as math. —I agree with you.A. more interestingB. most interestingC. the most interestingD.interesting ( )7. —Do you think yesterday's math problem was difficult?—Yes, I could ____ work it out.A．easily B．hardly C．finally D．nearly( )8．—Where shall we eat tonight?—Let's call Harry. He ____ knows the best places to go.A．only B．nearly C．seldom D．always( )9．Grace is pretty healthy because she ____ exercises and eats a lot of vegetables. A．never B．hardly C．sometimes D．often( )10．Tomorrow is Anna's birthday.Her mother is going to make a ____ meal for her.A．big B．common C．quick D．simple( )11. —How ____ Li Ming writes！—Yes, he is the ________ in our class. A．carefully；most careful B．careful；most carefulC．carefully；careful D．careful；careful( )12．Some of the tired students keep their eyes ____ in breaks.A．opened B．close C．closed D．open( )13. Many students say that if there were no examinations they should have ____ at school.A. the happiest timeB. a more happier timeC. much happiest timeD. a much happier time( )14．—We've no money and the last bus has gone. Any ____ ideas?—Oh, Tom'll drive home from work at this time. Ask him for a ride？A. funnyB. brightC. oppositeD. correct( )15. Steve isn't as ____ as Kelly.He often makes mistakes in his writing. A．careless B．tidy C．careful D．difficult( )16. My grandfather is over 80，but he is still in good health and stays ____．A．safe B．warm C．awake D．active( )17. —Do you like eating fish, Wang Han？—Of course. Nothing can be ____, I think.A．delicious B．beautiful C．more delicious D．more beautiful( )18. ____ you study, ________ grades you'll get.A．The hard；the good B．Harder；betterC．The harder；the better D．The hardest；the best( )19．Take care when you are driving, ____ in a summer storm like this. A．immediately B．especially C．probably D．recently( )20. —The song Where did the time go？tells us that our parents grow old withoutbeing noticed.—We should stay with them as ____ as possible.A．often B．soon C．little( )21. The cakes taste ____, and they sell ________.I will buy some.A．good；well B．well；well C．well；good( )22．We are so glad to see Meizhou is developing ____ these years than it did before.A．more quickly B．quicker C．most quickly D．the quickest( )23．—Which season do you like ____，winter or summer? —Summer. A．well B．better C．best D．the best( )24．—He was chosen to be a volunteer of the Olympic Games.—Great！No one speaks English ____ him.A．as beautiful as B．as badly as C．worse than D．better than( )25．I hear they are going to London, but I don't know ____ they will stay there. A．how soon B．how often C．how long D．how fast( )26．—Excuse me, would you please speak a little more ____？—Sorry, I thought you could follow me.A．sadly B．quickly C．politely D．slowly( )27. T o my surprise, my brother can speak English ____．A．lively B．perfectly C．badly D．friendly( )28. —Why do people there ____ use umbrellas in the sun？—Because they would rather enjoy the sunshine.A．hardly B．often C．always( )29. Mr Black used to be busy.But now he's retired and ____, so he has plenty of timeto exercise.A．hard B．calm C．free D．nervous( )30. Lucy is a(n) ____ student, she answers the teacher's questions _____in her class.A．more active；more actively B．active；more activelyC．more active；the most actively D．active；the most actively( )31. We'd better not eat too much ____ food because it's not only bad for our teeth, but also makes us fat easily.A．tasty B．delicious C．sweet D．cheap( )32．—These days I have always felt stressed.—You can ask Mrs Lee for help. It's ____ for her to solve your problem. A．necessary B．useful C．important D．possible( )33．—Are you ____, Mike? —Yes, Mom. Could you please get me some water? A．thirsty B．tired C．hungry D．sick( )34. I think my hometown is becoming ____．A. more beautiful and more beautifulB. more and more cleanerC. more and more beautifulD. clean and clean( )35. —Is there ____ about this place? —Yes. All the houses here are green. A．anything special B．special anything C．nothing special D．special nothing ( )36. The experiment was ____ easier than we had expected.A．more B．much more C．much D．more much( )37. All the children are talking and laughing in the living room, so it is ____．A．small B．noisy C．quiet D．big( )38. Canada is larger than ____ country in North America.A．any B．any other C．other D．the other( )39. John was so sleepy that he could hardly keep his eyes ____．A．opening B．be opened C．to open D．open( )40. —Jack, do you think time is money? —Yes, but I think it is ____ money. A．no important as B．not important asC．more important than D．much important than( )41. It takes a long time to by train, it's ____ by boat.A．quick B．the quickest C．much quick D．quicker( )42. —It's one of the ____ things in the world to stay with friends.—I agree with you. It always makes us comfortable.A．happiest B．worst C．busiest D．hardest( )43. —Peng Liyuan is ____ Chinese people as a beautiful and popular singer.—And now she is also the First Lady in China.A．famous as B．proud of C．famous for D．well known to( )44．She always finish her homework on time. She ____ leaves it till tomorrow.A．always B．never C．usually D．sometimes( )45．—Hi，Bob！I can't find my history book.Have you seen it ____？—Sorry, I haven't.A．somewhere B．everywhere C．nowhere D．anywhere( )46. The bag of rice is ____ heavy for the little boy to carry. Let's go and help him. A．so B．such C．even D．just( )47. How ____ the girls are playing！I really want to join them.A．happy B．happier C．happiest D．happily( )48．—Our teacher wants us to be ____ when we talk with the foreigners.—Yes, we should believe in ourselves.A．comfortable B．confident C．unusual D．energetic( )49．—Can I help you?—Well，I'm afraid the box is ____ heavy for you, but thank you all the same. A．so B．much C．very D．too( )50. —Terra，you shouldn't be so ____，you always leaves your things here and there.—Sorry, mom. I'll put them away soon.A．terrified B．cheerful C．careless D．embarrassed( )51. —Do you enjoy Han Lei's songs?—Yes.He is the winner of I'm Singer Ⅱ.I can't think of anyone with a ____ voice. A．better B．best C．more D．most( )52．—Can you understand me, T ony?—Yes, madam. You speak ________.I can follow you.A．enough clear B．clear enough C．enough clearly D．clearly enough ( )53．We don't want to speak badly or ____ in front of the class.A．clearly B．carefully C．carelessly D．properly。

Because,since,as,for的用法区别一、becausebecause是最常用的表示原因或者解释的连词，它可以连接两个句子，也可以连接一个句子和一个短语。

because后面的从句通常是主要的信息，而前面的主句通常是次要的信息。

例如：He was late because his car brokedown.（他迟到了，因为他的车坏了。

）She didn't go to school because of herillness.（她因为生病没有去上学。

）因为because后面的从句往往是重点，所以不建议在句首使用beca use，否则会显得语气弱或者不礼貌。

例如：Because I love you, I will do anything foryou.（因为我爱你，我会为你做任何事。

）（不推荐）I will do anything for you because I loveyou.（我会为你做任何事，因为我爱你。

）（推荐）二、sincesince通常表示已知或者显而易见的原因，而不是新的或者意外的原因。

例如：He must be rich since he drives aFerrari.（他一定很有钱，因为他开着法拉利。

）（已知或者显而易见的原因）He is rich because he won thelottery.（他很有钱，因为他中了彩票。

）（新的或者意外的原因）since可以放在句首或者句中，但是如果放在句首，通常要倒装主句和从句的顺序。

例如：Since he is the boss, he can do whatever hewants.（既然他是老板，他可以做任何他想做的事。

）（正常顺序）He can do whatever he wants since he is theboss.（他可以做任何他想做的事，既然他是老板。

）（倒装顺序）since还有一个意思是“自从”，表示时间上的起点，这时候它不表示原因或者解释，而是表示时间状语。

中考英语连接词表示因果关系用法单选题40题1.She didn't go to the party because she had a lot of homework to do.A.soB.butC.andD.or答案：A 选项so 表示“所以”，与题干逻辑相符；B 选项but 表示转折“但是”；C 选项and 表示并列“和”；D 选项or 表示选择“或者”。

题干中因为有很多作业要做所以没去参加派对，因果关系明显，所以选A。

2.He was late for school, so he ran quickly to the classroom.A.becauseB.butC.andD.or答案：A 选项because 表示“因为”，与题干逻辑相符；B 选项but 表示转折“但是”；C 选项and 表示并列“和”；D 选项or 表示选择“或者”。

题干中因为迟到了所以快速跑向教室，因果关系明显，所以选A。

3.She studied hard, so she got good grades.A.becauseB.butC.andD.or答案：A 选项because 表示“因为”，与题干逻辑相符；B 选项but 表示转折“但是”；C 选项and 表示并列“和”；D 选项or 表示选择“或者”。

题干中因为努力学习所以取得好成绩，因果关系明显，所以选A。

4.He didn't finish his homework, so he was punished by the teacher.A.becauseB.butC.andD.or答案：A 选项because 表示“因为”，与题干逻辑相符；B 选项but 表示转折“但是”；C 选项and 表示并列“和”；D 选项or 表示选择“或者”。

题干中因为没完成作业所以被老师惩罚，因果关系明显，所以选A。

5.She was tired, so she went to bed early.A.becauseB.butC.andD.or答案：A 选项because 表示“因为”，与题干逻辑相符；B 选项but 表示转折“但是”；C 选项and 表示并列“和”；D 选项or 表示选择“或者”。

初一英语原因状语从句because,as,since 用法辨析单选题30题1.I didn't go to school yesterday ____ I was ill.A.becauseB.asC.since答案：A。

解析：“because”表示直接的原因，语气最强。

因为生病是没去上学的直接原因，所以用“because”。

“as”和“since”表示的原因语气较弱，通常表示大家都知道的原因。

2.She loves reading ____ she can learn a lot from books.A.becauseB.asC.since答案：A。

解析：她爱阅读是因为能从书中学到很多，这里表示直接的原因，用“because”。

“as”和“since”在此语境中不恰当，不能准确表达这种直接的因果关系。

3.____ it was raining, we stayed at home.A.becauseB.asC.since答案：B。

解析：“as”表示较为明显的原因，这里因为下雨所以待在家里，原因比较明显，用“as”。

“because”语气太强，“since”也不太符合此语境。

4.____ you are tired, you should have a rest.A.becauseB.asC.since答案：C。

解析：“since”可以表示既然，这里既然你累了，就应该休息，用“since”比较合适。

“because”和“as”不太能表达“既然”这个意思。

5.I can't go out ____ it is too late.A.becauseB.asC.since答案：A。

解析：因为太晚了所以不能出去，是直接的原因，用“because”。

“as”和“since”在这个语境中不太能准确表达这种直接的因果关系。

6.She didn't go to the library because she had a lot of homework to do.As she had a lot of homework to do, she didn't go to the library.Since she had a lot of homework to do, she didn't go to the library.答案：三个句子都正确，意思相近。

九年级英语状语从句单选题40题1. I was doing my homework ______ my mother was cooking in the kitchen.A. whileB. whenC. asD. after答案：A。

本题考查时间状语从句中“while”和“when”的用法区别。

“while”强调两个动作同时进行，“when”既可以表示同时，也可以表示一个动作在另一个动作发生的过程中。

这里“我做作业”和“妈妈做饭”是同时进行的，所以用“while”。

“as”通常强调两个动作同时发展，“after”表示在……之后，不符合题意。

2. ______ I was walking along the street, I saw an old friend of mine.A. BeforeB. AfterC. WhenD. While答案：C。

“when”既可以指一个动作在另一个动作进行时突然发生，也可以指两个动作同时发生。

这里是“我正在沿着街走的时候突然看到了老朋友”，用“when”合适。

“before”在……之前，“after”在……之后，“while”强调两个动作同时持续进行，均不符合语境。

3. My sister was watching TV ______ I was reading a book.A. whileB. whenC. asD. until答案：A。

“while”表示两个动作同时进行，“我看书”和“我妹妹看电视”是同时发生的，用“while”。

“when”强调动作的突然性，“as”强调动作同时发展，“until”直到……，都不符合本题语境。

4. He was sleeping ______ the doorbell rang.A. whenB. whileC. asD. after答案：A。

“when”在此处表示一个动作在另一个动作进行时突然发生，“门铃响”这个动作在“他睡觉”的过程中突然发生，所以用“when”。

2.原因状语从句原因状语从句表示主句中动作或状态发生的原因或理由, 可位于主句之前,之后或插在主句中间。

主句表示结果, 从句表示原因, 主要由because, as, since, for,seeing ( that), considering ( that), now (that), in that, not ... because 等引导。

1) because“因为’’, as‘‘由于”, since “既然”, for“因为”because意为“因为”, 表示直接的原因或理由, 着重点在从句, 用于回答why,语气最强。

He is absent today because he is ill.当主句为否定句时, 从句because须用逗号与主句隔开, 否则容易引起歧义。

I didn’t visit him, because I wanted to borrow some books.我没去拜访他, 因为我想借几本书。

I didn’t visit him because I wanted to borrow some books.我不是因为想借几本书才去拜访他的。

as意为“由于”, 表示十分明显的原因, 所引导的从句常位于主句之前, 有时也可位于主句之后, 一般说明因果关系, 着重点在主句, 原因或理由只是附带说明, 不用于回答why的问题, 常用于口语。

As it is snowing, we shall not go to the park.As this book is written in simple English, it is suitable for beginners.since意为“既然, 由于”时表示对方已知的、无须加以说明的既成事实的理由, 只是一个附带说明。

since = as it is the fact that ...全句中心在主句。

如从句表示的原因不是确定的事实, 就不能用since,通常用because.Since everybody is here, let’s begin our discussion.Since you seem to know them, why don’t you introduce me to them?for是一个并列连词, 由for连结的表原因的句子常看作并列句, 它只提供一些补充说明或对前一个分句加以解释, 不可前置。

状语从句——原因状语从句★原因状语从句的时态:★原因状语从句的语序:★原因状语从句的引导词:常用引导词：because, since, as, for 特殊引导词：seeing that, now that, in that, considering that, given that.1. I didn’t go to school yesterday because I was ill. 我昨天没去上学，因为我生病了。

翻译：My friends dislike me bec ause I’m handsome and successful.既然大家都来了, 让我们开始开会吧.2. Since / Now that everybody is here, let’s begin our meeting.3. As you are in poor health, you should not stay up late. 既然你身体不好, 你就不该熬夜.4. I asked her to stay to tea, for I had something to tell her. 我请她留下来喝茶,因为我有事要告诉她.because引导的原因状语从句一般放于主句之后，表示直接原因或说明人所不知的原因，语气最强，最适合回答why 引导的特殊疑问句。

例如：I do it because I like it. 我做这件事是因为我喜欢。

注意： 1. “not ... because”结构中的not否定的是because引导的整个从句，例如：The country is not strong because it is large. 国强不在大。

2. 比较because与because of■从词性上看: because 是连词，+句子；because of 是复合介词，+名词、代词、动名词、what 从句(但不能接that 从句或没有引导词的句子)等。

辨析as, since, because 配套练习1. _____everyone is here, let’s start.A. BecauseB. SinceC. Because ofD. When解析：选B。

句意为：既然大家都在这里，那我们开始吧。

表示显而易见的原因，应该用since。

2. All of us should care more about our health _______ good health is the first step towards success.A. sinceB. becauseC. asD. for解析：选B。

句意为：我们所有人都应该更多的关注健康，因为健康是通往成功的第一步。

后句是前句的直接原因，语气强烈，要用because引导。

故选B。

3._______ you have not enough money, you can't buy that expensive car.A. SinceB. ForC. AsD. Because of解析：选A。

句意为：既然你没有足够的钱,你就不能买那辆昂贵的汽车。

since "既然",表示对方已知的无需加以说明的原因或事实,语气比because弱,但是比as 强。

4. Linda was angry, _______ she didn't know where her friend was.A. SinceB. ForC. AsD. Because of解析：选B。

句意为：Linda生气了，因为她不知道她的朋友去了哪里。

for引导的从句表示解释说明。

5. ________ you are busy, I’ll do it for you.A. SoB. SinceC. BecauseD. When解析：选B。

句意：既然你忙，我替你做吧。

since表示“既然”。

选项A表示“所以”；选项C表示直接的原因；选项D表示“当……时候”，根据题意选B。

英语因果句型的分类和用法一、因果连词因果连词是一种连接两个句子的词，表示前后句子之间的因果关系。

英语中常用的因果连词有以下几种：because：表示直接原因，语气最强，常用来回答why的提问，一般放在主句之后，也可以单独存在。

例如：I stayed at home because it rained. 因为下雨我呆在家里。

Because she was ill, Lisa didn't come to school. Lisa因病没有来上学。

since：表示显然的或已为人所知的理由，常译为“因为”、“既然”，语气比because稍弱，通常置于句首，表示一种含有勉强语气的原因。

例如：Since he is asking you, you'd better tell him why. 他既然在问你，你最好告诉他为什么。

Since everyone is here, let's set out. 既然大家都到齐了，我们就出发吧！as：表示双方已知的事实或显而易见的原因，或者理由不是很重要，含义与since相同，但语气更弱，没有since正式，常译为“由于，鉴于”。

从句说明原因，主句说明结果，主从并重。

例如：We all like her as she is kind. 我们都喜欢她，因为她善良。

As I had a cold, I was absent from school. 因为我感冒了，所以没去上课。

for：表示附加或推断的理由，不表示直接原因，语气最弱，较正式，只能放在句子后部，用逗号隔开，不能置于句首。

例如：The day is getting shorter and shorter, for it is December now. 白天越来越短了，因为现在已是十二月份。

It must have rained, for the ground is wet. (从“地面潮湿”作出“下过雨”的推测，但地湿并不一定是下雨所致, for不可以换为because。