原因和结果状语从句讲解-高三英语一轮复习素材.doc

高考英语语法总复习：原因和结果状语从句讲解<原因状语从句>原因状语从句是指在复合句中表示主句动作发生原因的句子。原因状语从句可置于句首,也可置于句尾。引导词有because, since,as,now(that)等。1.because引导的原因状语从句because引导的原因状语从句往往比主句显得更重要。表示动作发生的直接原因,表因果关系的语气最强,用来回答why引导的疑问句,所引出的原因往往是听话人所不知道或最感兴趣的。如:Why didn't you go with us today?你为什么今天没跟我们一起去?一 Because I was too tired.因为我大累了。He is leaving because he is fed up with the boss.他离开是因为他厌烦老板。I did not go to school yesterday because I was ill.我昨天没去上学,因为我生病了。Because it was raining,I had to stay at home.因为下雨,我只好待在家里。汉语里我们习惯说“因为所以”,但使用英语时不能将 because与so连用。表示因果关系时只能二选一。如:Because my bike was broken,so I went to school by bus yesterday. (误)I went to school by bus yesterday because my bike was broken. (正)My bike was broken,so I went to school by bus yesterday. (正)因为我的自行车坏了，所以我昨天坐公共汽车上学。Because my mother was ill, so I didn't go to your party(误)I didn't go to your party because my mother was ill. (正)My mother was ill, so I didn't go to your party. (正)因为我妈妈病了,所以我没去参加你的聚会。2. since 的用法since意思是“既然,由于,因为”,表示已知的、显然的理由,较正式,多位于句首。since引导的从句是次要的，重点强调主句的内容。Since tomorrow is LI Hong's birthday, lets give him party.既然明天是李宏的生日,咱们给他开一个派对吧。Since everyone is here, lets start our class.既然大家都来了,咱们就开始上课吧。since you are free, you'd better tidy your bedroom.既然你有空,你最好把卧室整理一下。Since it is late, I shall go home right now.(由于)时间不早了,我得马上回家。3.as的用法as与since用法差不多,所引出的理由在说话人看来已经很明显,或已为听话人所熟悉而不需用 because加以强调。as引导的从句与主句同等重要。As you were not there, I left a message.因为你不在那里,所以我留了个信儿。because,since和as的用法区别：和 because相比, since和as的语气稍弱。1)because语气最强,用来回答why引起的提问,可表示已知或未知的事实。它可和强调词only,merely,just及否定词not连用,所引导的从句常位于主句之后,只有强调时才置于主句之前。它还可用于强调结构。I did not go to school yesterday because I was ill.我昨天没去上学,因为我生病了。It was because I wanted to see my uncle that I wen to town yesterday.因为想去看叔叔我昨天才进城的。He was punished only because he broke the law.他就是因为触犯了法律才受到惩罚的2) since的语气也较弱。常表示对方已知的事实,相当于汉语的“既然”。之前不可用强调词和not,亦不可用于强调结构。Since everyone makes mistakes, you shouldn't always criticize him.既然每个人都会犯错误,你不应老是批评他。3)as语气最弱,较口语化。所表达的原因比較明显或是已知的事实,故不需要强调。之前不可用强调词和not,且不可用于强调結构。as从向多置于主向之前。As it was getting late, I turned around to start for home.由于天色渐晚,我就调头回家了。4.now(that)now(that)主要用于口语,表示微弱的原因,主从句因果关系不明显,常译为“既然”。Im going to relax now(that )the school year is over.这一学年结東了、所以我打算放松一下。Now( that)you have come, you may as well stay.概然你已经来了,那就留下来吧。<结果状语从句>在句子中作结果状语的从句称为结果状语从句一般置于句尾。常用的引导词或短语有so. that，such.that.等1.so.that.的用法。在so . that .句型中，so 后通常接形容词或副词，that后接从句，表示结果。如：My brother is so young that he cant look after himself.The singer sang so nicely that the audience clapped with excitement.当名词前有表示数量多少的many, much, few, little等词修饰时，通常用so . that句型。如：There are so many people on the bus that I cant find a seat.The piano costs so much money that Linda cant afford it.So.that.引导结果状语从句可以构成如下结构:So+形容词/副词+that+从句。So+many/few(+可数名词的复数)+that+从句。So+much/little(+不可数名词)+that+从句。So+形容词+a/an+可数名词单数+that+从句。Kathy is so lovely a girl that we all like to play with her.凯茜是个很可爱的女孩,我们都愿意和她玩。Father worked so hard that we were all Worried about him.父亲工作如此卖命,我们都为他担心。Tom is so kind that they all like to make friends with him.汤姆人很好,他们都愿和他交朋友。There's so little time left that we have to speed up几乎没时间了,我们只好加快速度。知识拓展So.that.引导结果状语从句时,从句结果是否定句,可与too.to.结构进行转换。They were w tired that they couldn't go any fatherThey were too tired to go any farther.他们累得不能再走了。You study so hard that You re sure to pass the exam.2.such.that.的用法在such . that .句型中，such 后通常接名词（词组），名词前可有形容词修饰，当名词是可数名词单数形式时，其前可有不定冠词，that 后接从句，表示结果。例如：Tom held such a meaningful activity that weall supported him.It was such bad weather that they couldnt go camping.such.that.引导结果状语从句,可以构成如下结构：such+a/an+形容词+可数名词单数+that+从句。such+形容词+可数名词复数+that+从句。such+形容词+不可数名词+that+从句。Kathy is such a lovely girl that we all like to play with her.凯茜是个很可爱的女孩,我们都愿意和她玩。These were such difficult questions that none of us could answer them.这些问题如此难,以至于我们之中没有一个人能回答上来。We had such terrible weather that we couldn't finish the work on time.天气这么糟以至于我们没能按时完成工作。知识拓展so/such.that.引导结果状语从句时可把so/such置于句首,主句用倒装语序。Such was his worry that he couldn't go on with his work.他如此担忧,以至于不能继续上班了。So carelessly did he drive that he was nearly killed他开车如此粗心,差点儿丧命。