before是什么意思

prep.
1. (表示位置)在…前面
2. (表示时间)先于, 在…以前
3. (表示比较)优于, 先于
4. (表示顺序)在…之前，（次序或排列）在前面
5. (表示目的)供…研究, 由…审判
6. 表示面临或临近
7. 当面
8. 表示面对某人、某事时的反应
conj.
1. 在…之前
2. 到…为止，到…之前
3. 以免；不然
4. （宁可…而）不愿
adv.
1. 先前; 从前; 以前；过去；已经

介词 prep.
1.(表示位置)在…前面
The man standing before the blackboard is our English teacher.
站在黑板前面的那个人是我们的英语老师。
2.(表示时间)先于, 在…以前
We got up before sunrise.
我们在太阳升起之前起床。
3.(表示比较)优于, 先于
You must pay attention to this problem before every thing.
你应该首先注意这个问题。
4.(表示顺序)在…之前，（次序或排列）在前面
My name comes before his on the list.
在名单上我的名字排在他的名字前面。
5.(表示目的)供…研究, 由…审判
The criminal case comes before the court.
那桩刑事案件已送法院审理。
6.表示面临或临近
7.当面
8.表示面对某人、某事时的反应
连接词 conj.
1.在…之前
It will be some time before we know the full results.
还要过一些时间我们才能知道全部结果。
2.到…为止，到…之前
3.以免；不然
4.（宁可…而）不愿
副词 adv.
1.先前; 从前; 以前；过去；已经
We saw that film before.
那部电影我们以前看过。
It came across my mind that I had met him somewhere before.
我突然意识到我曾在什么地方见过他。

before /bɪˈfɔː(r)/ DJ /bɪ'fɔr/ KK
preposition
(1)earlier than sb/sth 在…以前
before lunch 午餐前
the day before yesterday 前天
The year before last he won a gold medal, and the year before that he won a silver. 他前年得了一枚金牌，大前年得了一枚银牌。
She's lived there since before the war. 她从战前起就一直住在那里。
He arrived before me. 他比我先到。
She became a lawyer as her father had before her. 像她父亲先前一样，她成了一名律师。
Leave your keys at reception before departure. 离开前请把钥匙留在服务台。
Something ought to have been done before now. 先前就该采取措施了。
We'll know before long (= soon). 我们很快就会知道了。
Turn left just before (= before you reach) the bank. 在快到银行时向左拐。
used to say that sb/sth is in a position in front of sb/sth
(2)在…面前（或前面） rather formal
They knelt before the throne. 他们跪在御座前。
Before you is a list of the points we have to discuss. 放在你面前的是一份我们所要讨论的要点。
used to say that sb/sth is ahead of sb/sth in an order or arrangement (3)（次序或排列）在前面
Your name is before mine on the list. 名单上你的名字在我之前。
He puts his work before everything (= regards it as more important than anything else). 他一切以工作为重。
used to say that sth is facing sb in the future
(4)（表示面临或临近）
The task before us is a daunting one. 我们所面临的任务令人胆怯。
The whole summer lay before me. 整个夏季正等待着我。
in the presence of sb who is listening, watching, etc.
(5)当面
He was brought before the judge. 他被带上法庭。
She said it before witnesses. 她当着证人的面讲出这事。
They had the advantage of playing before their home crowd. 他们有在主场观众面前比赛的优势。
used to say how sb reacts when they have to face sb/sth
(6)（表示面对某人、某事时的反应） formal
They retreated before the enemy. 面对强敌，他们只好撤退。
conjunction
(1)earlier than the time when 在…以前
Do it before you forget. 尽早动手，免得忘了。
Did she leave a message before she went? 她走之前留言了吗？
Before I made a decision, I thought carefully about it. 我做的决定都是经过再三考虑的。
(2)until 到…为止；到…之前
It may be many years before the situation improves. 这种状况或许要过很多年才能得到改善。
It was some time before I realized the truth. 过了很长一段时间我才了解到真相。
(3)used to warn or threaten sb that sth bad could happen 以免；不然
Put that away before it gets broken. 把它收好，免得砸碎了。
(4)rather than （宁可…而）不愿 formal
I'd die before I apologized to them! 我宁死也不向他们道歉！
adverb
at an earlier time; in the past; already 以前；过去；已经

参考资料：

你好、是在…之前的意思、

　　除了……的以前外，还有在一段时间的意思，如：I play baseball before school. 的意思就是我打篮球在学校的每天。