英语状语从句收藏 （三）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, let’s 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, let’s 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”。
I’m going to relax now(that )the school year is over.
这一学年结東了、所以我打算放松ー一下。
Now( that)you have come, you may as well stay.
概然你已经来了,那就留下来吧。