before与since这两个单词在用法上的区别

before [bi'fɔ:]
a. 以前,在...以前
ad. 以前
prep.&conj. 在...以前
before [biˈfɔ:]
prep.在…前 conj.在…以前 ad.以前
before
Wiki
a.
1. 以前,在...以前
ad.
1. 以前
Come at two o'clock, not before.
两点钟来,不必再早了。
He was never late before.
过去他从不迟到。
Have you two met before?
你们两人以前见过面吗?
conj.
1. 在...以前
Get out before I call the police.
滚开,否则我叫警察。
I'd die before I'd tell.
我宁死也决不会说出来。
Check it carefully before you hand it in.
交来之前仔细核对一下。
prep.
1. [时间]...以前
the night before last
前晚
She said she had never spoken before an audience.
她说她从未在大庭广众讲演过。
Pride comes before a fall.
骄必败。
the day beforeyesterday
前天
before nine o'clock
九点以前
Only two days remained before the examination.
考前只剩下两天了。
Your name comes before mine.
你的名字在我之前。
before Christ
[缩写 B.C.]公元前
We will put the matter before the committee.
我将把此事提交委员会考虑。
2. [位置]在...的前面; 当...面前
He sat just before me.
他就坐在我的前面。
3. [位次]先于; 高于
A general comes before a colonel.
将官比校官高。
4. [选择]与其...宁愿
Death before dishonor!
宁死不辱。
She desired no one for husband before him.
她非他不嫁。
I've seen that film before.
我以前看过那部影片.
He will die before he submits.
他宁死不屈。
He always put the interests of others before his own.
他总把他人的利益放在第一位。
I have seen that film before.
那部电影我以前看过。
B comes before C in the alphabet.
B在字母表里排在C之前.
He made a statement before the House of Commons.
他在下议院当众发表了一个声明。
It will be a long time before we finish this dictionary.
我们需要很长的时间才能把这部词典编译完。
We had dinner after/before they arrived.
他们到达之后[之前]我们吃的饭.
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since
Wiki
ad.
1. 后来
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。
conj.
1. 既然,因为
Since it is so hot, let's go swimming.
既然天气这么热,我们去游泳吧。
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。
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。
prep.
1. 自... 以来, ...以后
since liberation
解放以来
I haven't heard from him since last year.
我自去年以来未曾收到过他的信。
We've been friends ever since we met at school.
自从我们在学校认识之后，我们就一直是好朋友。
She moved to London last May and has since got a job on a newspaper.
她去年五月?铰锥兀?酸嵋恢痹诒ㄉ绻ぷ鳌?
Where have you been since I last saw you?
自从我上次见到你以后, 你到哪儿去了?
It was the first time I'd won since I'd learnt to play chess.
自从我学会下国际象棋以来，这是我第一次赢。
Since you can't answer the question, perhaps we'd better ask someone else.
既然你无法回答这个问题，我们最好再问问别人。
I haven't eaten since breakfast.
我吃了早饭后到现在还什麽都没吃呢.
He had spoken to her only once since the party.
自从那次聚会以来, 他只跟她说过一次话.
How long is it since we visited your mother?
自从我们看望你母亲以来到现在有多长时间了？

since是自从的意思 before是在~~之前 一段时间 +since 表示从这个时间开始到现在---自从~~~以来 用法上It + ( 现在完成时 ) + 一段时间+ since + ( 一般过去时 ) 例句： 1. It is / has been four days since I caug...