as,for ,because都表示因为时，用法怎么区分

原因状语从句一般由because, since, as, for引导?注意as,because,since和for的区别:

　　①如果原因是构成句子的最主要部分,一般用because。because引导的从句一般不放在句子的开头。例如:

　　I missed the train because I got up late.

　　注:对于以why开头的问句,一般只能用because引导的从句来回答。

　　②如果原因已为人们所知,或不如句子的其余部分重要,就用as或since、since比as稍微正式一些。as和since引导的从句一般放在句子的开头。例如:

　　As he was not well,I decided to go there without him.

　　Since this method doesn't work, let's try another.

　　③for表示所说的理由是一种补充说明,因此,for引导的从句可以放在括号里,而且for引导的从句一般不放在句子的开头。例如:

　　I decided to stop and have lunch, for I was feeling quite hungry.







because, for, since和as

　　这四个词作为连词，都有“因为”的意思，都可以用来作为一个动作或情况提供原因或理由，但它们在用法上有区别：

　　because是从属连词，接表示直接原因的从句，往往放在句末(有时也放在句首)，直接明白地说明因果关系。因此，在回答why的提问时或原句有just, only, not…but all等副词强调原因时必须用because.

　　for是并列连语。接表示间接原因的并列分句，所说的理由是一种补充。说明for引导的句子一般放在句尾。试比较：

　　He isn't here today because he is ill.因为他病了，所以他今天没有来。

　　He must be ill, for he isn't here.他今天没来，看来一定是生病了。

　　since和as是从属连词，说明的是已为人们所知和理由。since的语气比because弱，但比as强。since和as引导的从句一般放在句子的开头。

　　Since he was busy, he didn't come.

　　他因为忙，所以没来。

　　As I have a day off today, I'll write to you.

　　因为我今天有一天假，所以就给你写信。

　　此外，since也可以述说推断的理。如：

　　It must have rained, since the ground is wet.

　　一定下过雨，因为地是湿的.








　because，since，as，for这些词在实际使用中都可以用做连词，当做“因为”、“由于”来讲，但要注意它们所表达意思的语气的顺序是be－cause，since，as，for，而且它们的具体用法还存在很大区别，我们千万不能混淆这四个词。

　　because表示“因为”，用来表示最直接的因果关系或是听话人所不知道的原因，它所表达的语气是这四个词中最为强烈的，它所引导的原因状语从句一般要放在主句之后。

　　还要注意两种情况也只能用because来回答：1、用why来提问的特殊疑问句的回答，只能用because；2、在强调句中，只能用because。

　　例：1、He　didn’t　attend　the　meeting　because　he　had　too　much　work　to　do.

　　2、It　is　because　it　rained　last　week　that　they　put　off　the　match.

　　since在语气上仅次于be鄄cause，更加强调“既然”、“由于”，用来表示大家已然知道的事实。

　　例：Since　we　have　no　money,we　can’t　buy　it.

　　as在语气上稍弱于since，不如since正式，而且经常用于口语。

　　例：As　he　wasn’t　ready　in　time,we　went　without　him.for是四个词当中表示“因为”、“由于”意思时语气最弱的一个，它实际只是对它前面的主句加以补充说明理由或推断原因，要用分号和前面的主句分开。

　　例：I　asked　hertostay　to　tea,　for　I　had　something　to　tell　her.

　　热身训练1、Why　was　he　late　for　school?____he　got　up　tool　ate.
　　A、Because　　B、Since　　C、As　D、For

　　2、"Is　David　at　school　today？""No,he　is　at　home____he　has　a　bad　cold."
　　A、because　　B、since　　C、as　　D、for

　　3、It　rained　last　night,___the　ground　is　wet.
　　A.because　　B.since　　C.as　　D.for

　　key：1、A2、A3、D







Because 多用于表示直接原因, 而 for 可以表示原因又可以用于提出说明, 语气比 because 轻得多。 Because 引导的从句一般放在主句后, 有时也可放在主句前, 而 for 引导的句子只能放在后面。



because
[bi5kCz, bE5kCz, bi5kEz]
conj.
因为
John didn't attend the meeting because he was ill.
约翰没有出席会议, 因为他病了。
B-he is tired, he does not want to go with us.
因为他太疲劳所以他不想和我们一起去。
I criticized him, not because I hate him but because I love him.
我批评他不是因为我恨他而是因为我爱他。



because of
因为; 由于; 为了(I didn't go out because of rain. 因为下雨, 所以我没有出去。)【说明】在 reason is 的后面, 人们常用that 而不用 because 开头的从句。



for
[fE(r), fC:(r)]
prep.
(1)
给；为
a present for Mary
给玛丽的礼物
I've got a little present for your birthday.
我有一件小礼物送给你过生日。
I can do it for myself.
我自己能做这件事。
These investigations are not done for nothing.
这些调查工作自然不是白做的。
(2)
以…为目的地；开往；前往
We set off for London.
我们动身去伦敦。
(3)
在…时间
She's coming for Christmas.
她在圣诞节来。
(4)
代；替；代表
Red is for danger.
红色代表危险。
What do you want for a present?
你要什么样的东西作礼物?
(5)
为了
for existence
为了生存
"Did you come to Paris for the purpose of simple leisure, or for business purposes?"
"你到巴黎来的目的纯粹是为了休闲,还是为了做生意?"
(6)
对于；关于
For him to forfeit his favourite hobby would be impossible.
要他放弃他所喜爱的业余爱好是不可能的。
I have no ear for music.
我对音乐外行。
For many of these families a college education was something new.
"对其中的许多家庭来说,大学教育是件新事物。"
(7)
因为
He's learning English for the fun of it.
他为了好玩才学习英语的。
for several reasons
因为种种原因
We bought this house with a much higher price than others just for its convenience.
"我们买下这幢房子花的钱比其它房屋要贵得多,就是图的方便。"
(8)
仅管
For all his efforts, he didn't succeed.
他虽然竭尽全力还是没有成功。
"For all your explanations, I understand no better than before."
"尽管你作了解释,我还是不懂。"
(9)
以…为价钱；付出
a pen for 50 pence 50
便士一枝笔
(10)
以…的价格，值
He paid 50 pence for the book.
他付了50便士买这本书。
(11)
经过（时间、距离）
We ran for two miles.
我们跑了两英里。
He stayed for a week.
他待了一周。
We haven't seen each other for ages.
我们好久没见面了。
(12)
用于for + 名词或代词 + to + 不定式动词的名词短语中
The bell rang for the lesson to begin.
开始上课的铃响了。



for example
例如
You can buy fruit here — oranges and bananas, for example.
你可以在这里买水果，例如买柑橘和香蕉。
"The government has reduced spending in several areas, for example in the construction of highways."
"政府已经在几个方面削减了开支,例如高速公路的建设。"

That's for you!
就是这样！

There's ... for you!
恰好相反
He just grabbed the money and left — There's gratitude for you!
他抓了钱就走，你可真会感激人！



since
KK: []
DJ: []
ad.(常用于现在完成时或过去完成时)
1. 此后;从那时到现在
She left school three years ago and has worked as a nurse ever since.
她三年前毕业,从那时起便一直当护士。
2. 之前,以前
prep.
1. (常用于现在完成时或过去完成时)自...以来,从...至今
I haven't heard from him since last year.
我自去年以来未曾收到过他的信。
conj.
1. (常用于现在完成时或过去完成时)自...以来,从...至今
It's been ten years since they married.
他们结婚到现在已经十年了。
She has been living a hard life since her husband died.
她自从丈夫死后,一直过着艰苦的生活。
2. 既然;因为,由于
He must have taken the book since it isn't here.
他一定是把书拿走了,因为书已不在这里了。
Since it is so hot, let's go swimming.
既然天气这么热,我们去游泳吧。




as
as 1
AHD:[2z] […z ] 非重读时
D.J.[#z][*z ]非重读时
K.K.[#z][*z ]非重读时
adv.（副词）
(1)
To the same extent or degree; equally:
同等地，一样地：同一限度或程度地；同等地：
The child sang as sweetly as a nightingale.
这孩子歌唱得同夜莺般婉转
(2)
For instance:
例如：
large carnivores, as the bear or lion.
大的食肉动物，如熊或狮子
(3)
When taken into consideration in a specified relation or form:
被认为：当在特别的关系或形式中加以考虑时：
this definition as distinguished from the second one.
这个定义与第二个有区别
conj.（连接词）
(1)
To the same degree or quantity that. Often used as a correlative after so or as :
像，如同：同等的程度或量，常用作关联词后置于so 或 as ：
You are as sweet as sugar. The situation is not so bad as you suggest.
你甜如蜜。情形不如你说的那样糟
(2)
In the same manner or way that:
以同样方式，以同样方法：
Think as I think.
像我这样去想
(3)
At the same time that; while:
同时；当…时：
slipped on the ice as I ran home.
我跑回家时在冰上滑了一跤
(4)
For the reason that; because:
由于；因为：
went to bed early, as I was exhausted.
睡得早，因为我精疲力尽了
(5)
With the result that:
结果：
He was so foolish as to lie.
他太傻才会撒谎
(6)
Though:
尽管：
Great as the author was, he proved a bad model. Ridiculous as it seems, the tale is true.
这位作者尽管了不起，到头来却成了一个坏榜样。这个故事看似荒唐，却是真的
(7)
In accordance with which or with the way in which:
根据或按照这一方法：
The hotel is quite comfortable as such establishments go. The sun is hot, as everyone knows.
就设备而言，这个旅馆相当舒适。太阳非常热，这一点众所周知
(8)
Informal That:
【非正式用语】 相当于that：
I don't know as I can answer your question.
我不知道能否回答你的问题
pron.（代词）
(1)
That; which; who. Used after same or such :
that；which；who。用在same 或 such 后：
I received the same grade as you did.
我和你得分一样
(2)
Chiefly Upper Southern U.S. Who, whom, which, or that:
【多用于美国中南部】 who，whom，which或that：
Those as want to can come with me.
想去的可以和我同去
prep.（介词）
(1)
In the role, capacity, or function of:
以…的身份，作为：充当角色、身份或功能的：
acting as a mediator.
充当调解人
(2)
In a manner similar to; the same as:
以相似的方式；如同：
On this issue they thought as one.
在这个问题上，他们意见一致

四者均可用来表示原因，区别如下：(1) 关于 because：语气最强，表示直接原因，可用于回答 why 提出的问题、引导表语从句、用于强调句等，而其余三者均不行：“Why didn’t he come?” “Because he was ill.” “他为什么没来?”“因为他病了。”My stomach hurts because I have eaten too many apples. 我肚子痛，因为苹果吃得太多。That’s because you can’t appreciate music. 这是因为你不能欣赏音乐。It is because he is honest that I like him. 是因为他诚实我才喜欢他。(2) 关于 since 与 as：a. 两者所表示的原因都是人们已知的，即对已知事实提供理由，而不是表示直接原因。since 比 as 语气稍强，且比 as 略为正式，它们引导的从句通常放在主句之前，有时也放在主句之后：As you weren’t there, I left a message. 由于你不在那儿，我留了个口信。Since you are wrong, you should apologize. 你既然错了，就应该道歉。b. since 可用于省略句，而其他三者不行：Since so, I have nothing to say. 既然如此，我无话可说。(3) 关于 for：是并列连词(其余三者为从属连词)，它有时可表示因果关系(通常要放在主句之后，且可与 because 换用)；有时不表示因果关系，而是对前面分句内容的解释或推断(也要放在主句之后，但不能与because 换用)。比较：The ground is wet, for (=because) it rained last night. 地面是湿的，因为昨晚下过雨。It must have rained last night, for the ground is wet this morning. 昨晚一定下过雨，你看今天早上地面是湿的。 (此句不能用 because 代 for)

选D
前面有个the reason了，所以ABC都不能选，不然就重复了
而且要是A可以选的话，BC也都可以选···排除法也可以得出D

D
表语从句
the reason why ……is that……

D:that

D

9. The reason ___ he is late is ___ there was a breakdown on the...
why that 第一个why 引导 同位语从句 that引导了 表语从句~另外：the reason why ... is that ... 这是很常用的一个固定搭配 意思是。。之所以这样的原因是。。。这个句子的意思是 他迟到的原因是因为铁路瘫痪了~祝你快乐~

请问这道题选择什么呢? 请详解一下
选A。第一个用why是因为reason后面表示迟到的原因，就用why，换成in which也是可以的；第二个是迟到原因的解释，就用that。其他的不说对不对，读起来语感也是不舒服的嘛

the reason why和the reason that有什么区别吗?
- "The reason that I didn't attend the meeting is personal."（我没有参加会议的原因是个人的。）- "He didn't come to the party due to the reason that he had other commitments."（他没有参加派对的原因是因为他有其他的事情安排。）总的来说，"the reason why" 用于提供更详细和...

reason , cause ,result ,怎么区别和使用?
〔例证〕She gave her reason for being late.她说出了迟到的原因。2、cause n. 起因，理由 〔辨析〕指导致某事发生的行为、事件等；也指产生某种感情或做出某种举动的正当理由，作此义解时常可与 reason 换用。〔例证〕Lack of physical exercise is the leading cause of obesity in young students...

why在定语从句中做原因状语时,可不可一换成that?
reason for which I was late.注意：在定语从句中当先行词为the reason(s)，定语从句由for which引导时，可以用why代替for which。由此我们得到句⑤He wanted to know the reason why I was late.请把下面两句话合并为一句，把第二句话变为第一句的定语从句。The reason is not very convincing.H...

he told her the reason--he is unhappy,but she doesn't believe t...
选B 两个都是定语从句 定语从句 的引导词取决于先行词在定语从句中做的成分 前者the reason 在定语从句中作原因状语 he is unhappy for the reason.所以引导词用why 后者the reason 在定语从句中作宾语 give her the reason（give 可跟双宾语)所以引导词用that 或which 或省略 ...

The reason is___he is unable to operate the machine。
选择 that 这是一个表语从句，然后从句 he is unable to operate the machine 又是一个完整的句子，不缺任何成分，所以用 that 引导， 谢谢 ，补充，答案很容易选择 why ,中式英语

for与reason有什么区别?
the reason for的用法举例：What is the reason for your absence yesterday?（你昨天缺席的原因是什么？）The reason for his success is hard work.（他成功的原因是努力工作。）She explained the reason for her late arrival.（她解释了她迟到的原因。）the reason of的用法举例：He is not ...

英语问题
【解答】This is the reason ___ he is late.【分析】这道题考察的是定语从句的知识。横线前面有先行词reason，而且有定冠词the作为路标词，he is late在横线后面而且基本句子成分完整。因此需要填关系副词 when, where and why中的一个，再结合句意，答案是B 【答案】B why 希望可以帮到你。

关于reason的定语从句 求高手讲解
很高兴为你解答。用why是定语从句,就是why后面跟的句子整个修饰reason.而that是同位语从句,整个句子对reason起到了补充说明的作用.好好体会一下,二者的意思是不同的.第一句是说他提供的理由不可接受，我们并不知道他提供的理由是什么。第二句是说.他迟到的原因是睡过头了，我们知道了这个理由。希望能...