since和for，as，because的区别

because,as,sinc的中文翻译_百度翻译
because,as,sinc
因为，因为，辛格
全部释义和例句试试人工翻译
because_百度翻译
because 英[bɪˈkɒz] 美[bɪˈkɔ:z]
conj. 因为;
[例句]He is called Mitch, because his name is Mitchell
人们叫他米奇，因为他大名叫米切尔。
双语例句 柯林斯词典

查一下哦语法书，龙江中考since

because
because引导原因状语从句语气最强，表示直接原因,常用来回答由why提出的问题，所引导从句可放在主句前，也可放在主句后。例如：
"Why did you do it?" "Because Carlos told me to".
We can't go to Julia's party because we're going away that weekend.
Because he didn't catch the last bus, he had to walk home.
Why are you late for school ? Because I missed the first bus.

as
as “由于,鉴于” 主从并重，从句说明原因，主语说明结果。说明比较明显的原因。多用于日常语中，常译为“由于”，从句一般放于主句前。例如：
You can go first as you're the oldest.
As you don't feel well, you had better stay at home.
As he wasn't ready in time, we went without him.
I must stop writing now, as I have rather a lot of work to do.
As it was getting late, I decided to book into a hotel. As it is raining, you'd better take a taxi.

since
since “因为,既然” 侧重主句，主句表示显然的或已知的理由。强调说话者和听者双方都知道的原因，常译为“既然”，一般用在这样的句子里。例如：
Since we've got a few minutes to wait for the train, let's have a cup of coffee.
Since you are not feeling well, you may stay at home.
Since everybody is here, let's begin the meeting.
Since I am a boy, let me carry the case.
Since/As you are busy, you had better not go with us.
Since we have no money, we can't buy that vase.

for
for “因为,由于”表明附加或推断的理由，引导的分句前常有逗号。for分句不放句首.是用来附带解释或说明前一分句的原因和理由。例如：
Day breaks, for the cock crows.
It must have rained last night, for the ground is wet.
I won't go in, for my father is there.
He must be ill, for he is absent.
I went to see him, for I had something to tell him.

because／since／as／for这四个词都是表示原因或理由的连接词，但是as，because，since是从属连词，引导原因状语从句，for是并列连词，所引导的不是原因状语从句，而是表示理由的对等句子，是对前面所讲内容补充和说明。在语气上由强至弱依次为because→since→as→for。because引导的从句多置于句末，表示直接的原因或理由，表示产生那种结果的必然的因果关系，在回答why的提问时，必须用because作答。
如：We stayed at home because it rained．因为下雨我们呆在家里。
as与since引导的从句多置于句首，不过as表示十分明显的原因，只说明一般的因果关系，可译为“因为、由于”；而since则表示稍加分析、对方已知的原因，一般可译为“既然”。如：
As he was not feeling well，I decided to go there alone．由于他身体欠佳，我决定独自去那里。
Since everyone is here，let';s start．既然大家都到了，咱们就开始吧。
for引导的分句一般放在句末，其前用逗号，它所叙述的理由是间接的，即推测性理由，或是对前面叙述的事实或看法的补充说明。如：
There must be nobody in the classroom，for the light is off．教室里一定没有人，因为灯灭了。（推测性理由）转自网上，供参考：
because,since,as,for?
because／since／as／for这四个词都是表示原因或理由的连接词，但是as，because，since是从属连词，引导原因状语从句，for是并列连词，所引导的不是原因状语从句，而是表示理由的对等句子，是对前面所讲内容补充和说明。在语气上由强至弱依次为because→since→as→for。because引导的从句多置于句末，表示直接的原因或理由，表示产生那种结果的必然的因果关系，在回答why的提问时，必须用because作答。
如：We stayed at home because it rained．因为下雨我们呆在家里。
as与since引导的从句多置于句首，不过as表示十分明显的原因，只说明一般的因果关系，可译为“因为、由于”；而since则表示稍加分析、对方已知的原因，一般可译为“既然”。如：
As he was not feeling well，I decided to go there alone．由于他身体欠佳，我决定独自去那里。
Since everyone is here，let';s start．既然大家都到了，咱们就开始吧。
for引导的分句一般放在句末，其前用逗号，它所叙述的理由是间接的，即推测性理由，或是对前面叙述的事实或看法的补充说明。如：
There must be nobody in the classroom，for the light is off．教室里一定没有人，因为灯灭了。（推测性理由）

三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，而其余两者均不行：
“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：
1）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。
2） since 可用于省略句，而其他两者不行：
Since so, I have nothing to say. 既然如此，我无话可说。