1、9AUnit5GrammarA&B（原因状语从句）英语中按句子的结构可分三种：简单句 (simple sentence)；并列句 (compound sentence)和复合句 (complex sentence)。简单句：只有一个主语（或并列主语）和一个谓语（或并列谓语）。e.g. He often reads English in the morning. Tom and Mike are American boys. She likes drawing and often draws pictures for the wall newspapers.并列句：由并列连词（and, but,
2、 or等）或分号（;）把两个或两个以上的简单句连在一起构成。e.g. You help him and he helps you. The future is bright; the road is tortuous. 前途是光明的，道路是曲折的。复合句：主句+从句（含有一个或一个以上从句）。主句是一个完整的句子(independent sentence),它可以独立存在。从句是一个不完整的句子,它必须和一个主句连用，不能独立存在。复合句包含：名词性从句（主语从句、宾语从句、表语从句和同位语从句）、定语从句和状语从句等。中学生英文写作中经常使用的从句有：宾语从句, 状语从句和定语从句。今天，我
3、们就来看看状语从句(Adverbial Clauses)。状语是句子的重要修饰成分，一般由副词、介词短语、分词和分词短语、不定式或相当于副词的词或短语来担当。从情况、时间、处所、方式、条件、对象、肯定、否定、范围和程度等方面对谓语中心词进行修饰或限制，用来说明地点、时间、原因、目的、结果、条件、方向、程度、方式和伴随状况等，其位置一般放在句末，但也可放在句首或句中。在复合句中作状语的句子叫状语从句。状语从句在主从复合句中作状语，修饰主句中的动词、形容词或副词，按意义可分为时间、地点、原因、目的、结果、条件、行为方式、比较、让步等九种状语从句。一般位于句首或者句末，位于句首，用逗号和主句隔开。现
4、在，我们一起来学习原因状语从句（Giving reasons with “because,since and as”）。Grammar A-Giving reasons with “because”. 1、because是从属连词，表示直接原因，常译为“因为”，其语气最强。常用来回答why的提问。如： *I stayed at home because it rained. 因为下雨我呆在家里。 *Why is she absent? Because she is sick. 她为什么缺席？因为她病了。*Because he was ill , he was absent yesterday.
5、2、because+句子；because of+短语。如：1.) -Why are you late? - _Because_ there is too much traffic.2.)Tan Dun has succeeded in Music _because of_ his efforts .3、because和so不能同时使用，because通常放在表示原因的句子前，so通常放在表示结果的句子前。如：I want to share the best art with people, so I am always searching for something better or dif
6、ferent.=Because I want to share the best art with people, I am always searching for something better or different.Grammar B-Giving reasons with “since and as”.1. since是从属连词，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，但是比as 强。通常置于句首。如： *Since he asks you, you just tell him why. 他既然问你，那就告诉他为什么吧。 *Since e
7、veryone is here, lets start. 既然大家都到齐了，我们就出发吧！*Since she has no time , she cant go with you.*Since we have no money, we cant buy that vase.既然我们没钱，我们就不能买那花瓶。 2. as是从属连词，表示的“原因”是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，常译为“由于，鉴于”。它引导的从句通常放在句首，有时也可放在句末。如： *As I had a cold, I was absent from school. 因为
8、我感冒了，所以没去上课。 *As it was getting late, I decided to stay here.因为天色已晚，我决定呆在这儿。 *As you are busy , I wont waste your time.*As it is raining, youd better take a taxi. 天下雨了，你最好乘出租车。原因状语从句小结：1、该类从句的引导词有because,since 和as等。2、强调未知原因回答why提问常使用because，通常放在主句后，也可放在主句前面。3、表示已知的、显然的理由，常使用since 和 as，通常放在主句前。4、beca
9、use和so不能同时使用。知识拓展：1、 because, as, since引导原因状语从句的区别。because 表示的原因因果关系很强, as 和 since表示已知的或比较明显的原因，译为“由于”“既然”，since 比 as 更正式，as 从句有时候可以倒装。2、在强调句中强调原因状语从句，只能用because引导，不可用as或 since，如： It was because he was ill that he didnt go with us.3、because可以引导表语从句，而 as, since不可以，这时主语一般都是it, this, that。 如：Its becaus
10、e he is too lazy.4、Tired as he was, he went to bed early. ( as 倒装表示原因) 5、for也有“因为”之意，是并列连词，语气较强。用来附带解释说明前一分句的原因理由或用来表示推断的依据，前面常带逗号。for引导的并列句，一般放在所要说明的句子的后面。如：I went to see him, for I had something to tell him.我去见他，因为我有事要告诉他。It must have rained last night, for the ground is wet6、原因状语从句如果主语一致，可以略为分词短语
11、、介词短语或者独立结构等。Being the eldest, Bill looks after his little sisters. (省略As he is)巩固练习：一、单项选择()1. _ his right hand was hurt, _ he wrote slowly.A. Because; so B. Because; / C. Although; but D. Although; /()2. _ she had no money to afford the expensive car, she had to give it up.A. So B. Before C. Until
12、 D. Since()3. (2019无锡) The local food may taste a bit strange.Well, _ we are here, why not give it a try?A. though B. unless C. since D. because()4. _ is the street so crowded?Because many people are watching the boat race. A. Why B. Where C. How D. Who ()5. Tom, why are you so unhappy?I didnt get f
13、ull marks in the exam _ carelessness.A. since B. because of C. as a result D. in order to()6. _he took the brush away, he_ some paint onto the paper.A. As; dropped B. Because of; droppedC. As; dropping D. Since; drop()7. Its hard for us to say goodbye _ we have so many happy days to remember.A. so B
14、. because C. unless D. until()8. _ he is almost 70, he still plans to go to college.A. Unless B. If C. Though D. Since()9. _ you can sing well, please sing a song for us.A. Because B. Since C. Though D. When()10._ do you buy so many film tickets? Because all of us are going to the cinema together.A.
15、 Why B. What C. How D. Who()11. _ my bike was broken, _I went to school by bus yesterday.A. Because; / B. Because; so C. Although; but D. Although；/()12. _ at the dark clouds in the sky, he decided to stay at home.A. To look B. Looking C. Looked D. Looks 二、同义句改写。1.-Why are you late? - Because there is too much traffic.=-Why are you late? - _ _ too much traffic.2. I didnt go to school yesterday because it rained heavily.=I didnt go to school yesterday _ the rain was _.=I didnt go to school_ _ the _rain.=It rained heavily, _I didnt go to school yesterday.
