第1个回答 2009-01-31
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.
-----------------------------------------------------------------------------
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？
第2个回答 2015-10-24
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 caught a cold. 我感冒已四天了.
2. It is / has been two weeks since we met last. 自从我们上次见面以来已过了两周.
一段时间 + before
表示在这个时间之前,或者大约在这个时间上就会发生某事
用法上It + ( 一般将来时 ) + 一段时间+ before +( 一般现在时 )
例句：
It will be five years before he meets you again.
五年之后他就会再见你的.
It + be (not) + long before
表示"(不)很久 / 才…"或"(没)过多久就 / …"
It was (not) long before …. (谈论过去)
It will (not) be long before ….(谈论将来)
It was long before she came back.
没过多久她就回来了.
It will be long before we meet again.
很久以后我们才会再见面.
It will not be long before we turn our hope into reality.
过不了多久我们的希望就会变成现实.
这里it指时间,before是连词,引导时间状语从句.long可用一段时间来替代.
第3个回答 2015-10-01
一、可以用作介词
⒈)指时间上早于，在……之前，如：
She has lived here since before the war.
她从战前就一直在这儿住。
⒉)指位置在前面，如：
We knelt down before Grandma‘s grave.
我们在奶奶的墓前跪下。
⒊)指顺序或排列在之前，如：
Your name comes before mine on the list.
名单上你的名字在我之前。
⒋)在某人面前，如：
She said it before the witness.
他是当着证人的面说的。
二、作为连词
其基本含义是“在……之前”，又可以根据不同语境灵活翻译成“才”、“还没来得及就……”、“趁……”、“就”等。具体用法如下：
⒈)与情态动词can/could连用
这时候从句虽为肯定形式，根据汉语表达习惯译成“还没来得及就”，如：
Before I could get in a word，he had measured me.
我还没来得及插话他就为我量好了尺寸。
Before she could move，she heard a loud noise，which grew to a terribl eroar.
她还没来得及迈步，就听见一声巨响，接着就是可怕的隆隆轰鸣。
⒉)用于肯定句中强调主句所表达的时间，距离长，或花费的精力大，译成“才”
We had sailed four days and four nights before we saw lands.
我们航行了四天四夜才看到陆地。
We waited a long time before the train arrived.
我们等了很长时间火车才到。
⒊)用于否定句中，强调主句所表达的时间，距离短，或花费的精力小，译成“不到……就”如：
We hadn‘t run a mile before he felt tired.
我们跑了还不到一英里他就累了。
⒋)主句含有hardly，scarcely等半否定副词时可以译为“刚……就”
这时候主句应用过去完成时态，从句用过去时，还可以用when替代before如：
We had scarcely reached the school before/when the bell rang.
我们刚到学校铃声就响了。
⒌)有时还有“宁愿”的意思
I‘d shoot myself before I apologized to him.我宁死也不向他道歉。
⒍)用于It+be/take+时间段+before句型
在这一句型中又可以根据主从句的时态分成两种情况。
若主句是一般时将来时态，从句是一般现在时.若主句是肯定句意思是“要过多长时间才”；若主句是否定形式翻译成“用不了多久就”。
It will be two weeks before everything returns to normal.
两周之后一切才能恢复正常。
It will be many years before the situation improves.
这种状况或许要过许多年才能得以改善。
It won‘t be long before we meet again.用不了多久我们就会再见面的。
这时若主句是一般过去时从句也是一般过去时。若主句是肯定句翻译成“多长时间之后才”，若主句是否定形式翻译成“没过多久就”。如：
It was some time before I realized the truth.
过了很长一段时间我才了解到真相。
It wasn‘t long before she became a brave solider.
没过多久她就成了一名勇敢的战士。
After that it still took seven years before they got married.
他们又过了七年才结婚。
注意：当主句的谓语动词为延续性动词时，before与until有时可以互换。It was an hour before/until the police arrived.
■巩固练习
⒈(2004天津)It was evening ________ we reached the little town of Winchester.
Athat B.until C.since D.before
2.(2004全国)Several weeks had gone by ________ realized the painting was missing.
A.as B.before C.since D.when
3.(2005广东)The America Civil War lasted four years ______ the North won in the end.
A.after B.before C.when D.then
4.(2005山东)It was some time _______ we realized the truth.
A.when B.until C.since D.before
5.(2006四川)-Why didn‘t you tell him about the meeting？
-He rushed out of the classroom _______ I could say a word.
A.before B.until C.when D.after
6.(2006福建)-How long do you think it will be __ china sends a manned spaceship to the moon？
-Perhaps two or three years.
第4个回答 2016-02-15
since 和 before有什么区别？虽然两个单词同属连词, 但两者却有着截然不同的意思。 since 表达的是： “从什么时间开始，" 即”从过去的某个时间以来。" 而 before 则表达的是：“在过去某个时间之前。”以下为你提供两个例句：
Since the 1980s, China started its economic reform.
Before the 1980s, There was no economic reform in China.
在这两个例句中， since 和 before 在时间上所表现出的区别，可以用以下的图表来阐述：
【1980s 是时间坐标】《------------- before the 1980s / since the 1980s-------------》