since和as的问题1、since在什么情况下是“因为”的意思,什么情况下是“自从”的意思2、as在什么情况下是“因为

楼主您好、一下为两个单词.


since英音：[sins]美音：[sɪns]

副词 ad.v (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

介词 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.

连接词 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.



语法标注解释 as英音：[æz]美音：[æz]

as
副词 ad. v

1.跟...一样地,同样地
Sam is as rich as Alexander.
山姆像亚历山大一样富有.
2.如同;例如
Such animals as foxes and squirrels have bushy tails.
有些动物,如狐和松鼠,有蓬松的尾巴.

介词 prep.

1.作为,以...的身份
She works as an interpreter in that company.
她在该公司里担任翻译员.
2.当作
She didn't think much of him as a painter.
她对他作为一位画家评价不高.
3.像;如同
The old woman was dressed as a young lady.
这位老妇人打扮得像一位年轻人.

连接词 conj.

1.像...一样;依照;像
You ought to do as Paul tells you.
你应按照保罗吩咐的做.
The work is not so difficult as you imagine.
这工作不像你想像的那么困难.
2.当...时
As she left the room she remembered that book.
她离开房间时想起了那本书.
3.随着
As the sun rose the fog dispersed.
太阳一出来,雾随之消失.
4.因为
We didn't know what to do as we were just visiting there.
我们不知道该怎么办,因为当时我们仅仅在那里作访问.
5.虽然
Tired as he was, he sat up late.
他虽然疲倦,可仍然很晚才睡.

代词 pron.

1.(与such,the same,as等连用,引导关系从句)与...相同的事物(或人)
He has earned as much money as I have.
他赚的钱和我赚的一样多.
She felt just the same as he did.
她和他的感受相同.
There is a general rise in prices such as occurred in the late 60's.
物价普遍上涨,跟六十年代末一样.
2.(引导从句,对前述内容作补充)本情况,该事实
She has married again, as was expected.
她已再婚,这是意料中的事.
We are tired, as anyone can see.
我们累了,这是有目共睹的.

希望能给您帮助.

您好！
1.since 后面接了表示时间的状语时，是自从的意思。而作为因为讲时，一般没有时间状语。
I have not heard from him since writing last.
自上次写信以后， 我没有接到过他的信。
Since you have no spirit, I have to settle for beer.
既然你没有烈性酒，...