as,for ,because都表示因为时,用法怎么区分
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发布时间：2022-04-25 15:51
共3个回答
热心网友
时间：2023-10-14 18:48
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 ecation 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 reced spending in several areas, for example in the construction of highways."
"*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*。
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
热心网友
时间：2023-10-14 18:48
You can trust those procts because the quality never changes.
I haven”t been to the cinema lately, because I am too busy.
I didn”t go, because I was afraid.
2）当原因是显而易见的或已为人们所知，就用as或 since。since稍正式一些。
Since /As the weather is so bad, we have to delay our journey.
3） 由because引导的从句如果放在句末，且前面有逗 号，则可以用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。
He is absent today, because / for he is ill.
He must be ill, for he is absent today.
4）当because引导的从句与否定的主句连用，而主句又位于句首时，之前不用逗号，因为主句动词否定的是其后的全部内容。为了突出 because从句，because 前常加上副词，如：just, only, simply, chiefly等。在这种情况下，常常会形成否定的转移。如果是在口语中，在because前要有一个停顿（逗号），才能表示出否定没有转到 because从句中。如：
You should not despise a man just because he is poorly dressed.
She is not marrying Bill, because he is poor.
热心网友
时间：2023-10-14 18:48
since:因为.强调双方已知无需用说明的事由.
for:因为.强调一种推测.但不一定是事实.
as:强调一般因果关系.用于句首.
Because she's ill,she can't go to my home.因为她病了,所以她没有来我家.
注:because后接句子,而because of后接短语.
Since everyboby is here,let's begin our meeting.
既然大家都到了,那就开始开会吧.
Day breaks,fro the birds are singing.
因为鸟儿在唱歌了,天可能亮了.
As he was not well,i decided to go without him.
由于他身体不太好,我决定不带他去.
