原因状语从句

1、because, since, as, for,这几个词都是这几个词都是表示表示“原因原因”的连词，语气由强至弱的连词，语气由强至弱依次为：依次为：becausesinceasfor 其中其中because, since, as均为从属连词，均为从属连词，引导原因状语从句；而引导原因状语从句；而for 是并列连词，是并列连词，引导并列句。引导并列句。 I stayed at home because it rained. Why is she absent? Because she is sick. 在强调句型中，只能用在强调句型中，只能用because It was because I mi

2、ssed the early bus that I was late for school. 要点：不要把连接词要点：不要把连接词 because与介词与介词短语短语because of ( + 名词或名词或-ing形式形式) 相混淆；相混淆；He lay in bed because he had caught a bad cold. He lay in bed because of a bad cold.since表示显然的或已为人所知的理由，表示显然的或已为人所知的理由， 常译为常译为“因为因为”、“既然既然”，通常置于句首，通常置于句首，表示一种含有勉强语气的原因。表示一种含有勉强语气

3、的原因。 Since he asks you, youll tell him why. Since everyone is here, lets start. as含义与含义与since相同，但语气更弱，相同，但语气更弱，没有没有since正式正式 We all like her as she is kind. As I had a cold, I was absent from school. for表明附加或推断的理由表明附加或推断的理由,它所引导的它所引导的分句只能放在句子后部分句只能放在句子后部 ,并且前后两个并且前后两个分句间的逻辑关系不一定是因果关系分句间的逻辑关系不一定是因果关系

4、,其间用逗号隔开其间用逗号隔开.The days are short, for it is now December. It must have rained, for the ground is wet. now that 既然既然 . 常放句首常放句首.Now that you have left university, you will have to find a job. Now that everybody is here, lets begin the discussion. 1.Dont be afraid of asking for help _ it is needed.

5、A.unless B.since C.although D.when2.Mary was making a dress _ she cut her finger. A. when B. while C. as D. after3.It was _ back home after experiment . A. not until midnight did he go B. until midnight that he did not goC. not until midnight that he went D. until midnight when he did not go4. Unlik

6、e watching TV, reading is a highly active progress (过程过程) ,_ it requires attention as well as memory and imagination. A. until B. but C. unless D. for5.She thought I was talking about her daughter, _ ,in fact, I was talking about my daughter. A. whom B. where C. which D. while6._ quite recently, mos

7、t mothers in Britain did not take paid work outside the home. A.Before B. Until C. From D. Since7._ you are leaving tomorrow, we can eat dinner together tonight.A.For B. Since C. Before D. While 8.Mr Brown returned home just _ his family were having supper.A then B as C when D while9. _he took part

8、in the competition, he won a second prize.A The first time B For the first time C At the first timebecause 1. 语气强，可放在主句前或后，表示语气强，可放在主句前或后，表示直接因果关系，回答直接因果关系，回答why 提出的疑问提出的疑问句，用在强调句式结构中。汉语中的：句，用在强调句式结构中。汉语中的：“因为因为-所以所以-”在英语中的表在英语中的表达只能使用达只能使用because 或或so 中的一个，中的一个，不能同时使用这两个单词。不能同时使用这两个单词。1. 那个男孩因病缺席。那

9、个男孩因病缺席。 The boy was absent because he was ill. It was because he was ill that the boy was absent. 2.- Why cant you go there now? - _ Im too busy. 3.(True or false) Becuse I had nothing better to do, so I decided to go to Wufeng Mountain with them. because 要点：不要把连接词要点：不要把连接词 because与介与介词短语词短语because

10、 of ( + 名词或名词或-ing形形式式) 相混淆；相混淆；He lay in bed because he had caught a bad cold. He lay in bed because of a bad cold.1.Tom was late for school. Thats _ he got up too late. 2. Tom got up too late. Thats _ he was late for school. this is / that is / it is because 后面后面接原因。接原因。 this is / that is / it is

11、why 后面接结后面接结果果- Who knows where Terry is?- The reason _ Terry is absent is _ his father had an accident. A why ; because B why ; that C that ; because D that ; /as 表示十分明显的原因，一般说明表示十分明显的原因，一般说明因果关系，着重点在主句，语气比因果关系，着重点在主句，语气比because 弱，常译为弱，常译为“由于由于”。as 引导的从句可放在句首或句末。引导的从句可放在句首或句末。1. 由于正在下雪，我们不去公园了。由于正在

12、下雪，我们不去公园了。 As it is snowing , we shall not go to the park. 2. 由于我没有读过这本书，所以我无由于我没有读过这本书，所以我无法告诉你有关它的事情。法告诉你有关它的事情。 As I have not read the book, I cannot tell you anything about it. 1. (2012重庆重庆) - Coach, can I continue with the training? - Sorry, you cant _ you havent recovered from the knee injury

13、. A until B before C as D unless2. Do _ you are told to, or youll be fired. A as B while C before D since 3. _ the day goes on, the weather is getting colder and colder.A With B Since C While D As变成变成with的复合结构的复合结构 With the day going on 3. since 一般表示对方已知的，无需一般表示对方已知的，无需加以说明的既成事实的理由，全句中加以说明的既成事实的理由，全

14、句中心在主句，语气比心在主句，语气比because 和和as 弱，弱，常译为常译为 “既然既然”。now (that)与与since 意思接近，表示意思接近，表示“既然，鉴既然，鉴于于”。表示一种含有勉强语气的原因。表示一种含有勉强语气的原因。since 和和now that 引导的从句常放在引导的从句常放在句首。句首。1. 既然你要去，我也要去。既然你要去，我也要去。 Since you are going, I will go.2. Since you are grown up, you should not rely on your parents. 1.(2005北京北京) It is

15、 almost five years _ we saw each other last time. A before B since C after D when 2. (2011四川四川) As is reported, it is 100 years _ Qinghua University was founded. (when before, after, since)3. - How long is it _ he arrived here?- About half an hour, I suppose.A since B before C when D after 1. (NMET1

16、999)_ youve got a chance, you might as well make full use of it. A Now that B After C Although D As soon as 2. _ no one has read the book, we cant discuss it.3. _ the rain has stopped, lets go home at once. (since, now that)A Since Now that1. 既然雨已停了，让我们立刻回家吧。既然雨已停了，让我们立刻回家吧。 Now that the rain has st

17、opped, lets go home at once. 2. 既然没有人读过这本书，我们就不既然没有人读过这本书，我们就不能对它进行讨论。能对它进行讨论。 Since no one has read the book, we cant discuss it. for 意思是意思是“因为因为”，但它不是从属，但它不是从属连词，而是并列连词，是用来说明，连词，而是并列连词，是用来说明，补充解释或表示一种推理，它所引导补充解释或表示一种推理，它所引导的分句只能放在句子后部的分句只能放在句子后部 ,并且前后并且前后两个分句间的逻辑关系不一定是因果两个分句间的逻辑关系不一定是因果关系关系,其间用逗号隔

18、开其间用逗号隔开.1. 我们得早点出发，因为我们有很长我们得早点出发，因为我们有很长一段路要走。一段路要走。We must start early, for we have a long way to go. It must have rained last night, for the ground is wet. 1. (2008山东山东) He found it increasingly difficult to read, _ his eyesight was beginning to fail. A though B for C but D so 2. （2006湖南）湖南）A man cannot smile like a child, _ a child smiles with his eyes, while a man smiles with his lips