before的例句是：用作前缀(pref.)B comes before C in the alphabet.B在字母表里排在C之前。before的详尽释义是conj.(连词)在...以前与其...宁可。before的词语用法是prep.(介词)before可用于表示时间。首先，可以表示“先于，在…以前”，其后可以跟表示具体日期、时间等的名词或数词，也可以跟表示时间或动作的名词。其次，可以表示“在做…之前”，后接 v -ing。再次，可以表示“紧接在…之前”。before用于否定句还可表示“直到…为止”。注意before之后只能接表示时间点的名词，而不能接表示时间段的名词。
一、详尽释义点此查看before的详细内容
二、双解释义
三、词典解释
1.（时间上）在…之前，早于
If something happensbefore a particular date, time, or event, it happens earlier than that date, time, or event.
e.g. Annie was born a few weeksbefore Christmas...
安妮出生在圣诞节前几周。
e.g. Before World War II, women were not recruited as intelligence officers...
在第二次世界大战之前，女性不能当情报人员。
2.在（做某事）之前
If you do one thingbefore doing something else, you do it earlier than the other thing.
before的解释
e.g. He spent his early life in Sri Lankabefore moving to England...
在移居英格兰之前，他早年是在斯里兰卡度过的。
e.g. Before leaving, he went into his office to fill in the daily time sheet.
离开前，他到自己的办公室填写了日常考勤表。
3.在（某时间或某事）以前
You usebefore when you are talking about time. For example, if something happened the daybefore a particular date or event, it happened during the previous day.
before
e.g. The war had ended only a month or sobefore.
战争大约一个月前才刚刚结束。
4.在（他人做某事）之前
If you do somethingbefore someone else can do something, you do it when they have not yet done it.
e.g. Before Gallacher could catch up with the ball, Nadlovu had beaten him to it.
加拉赫还没来得及追上球，纳德洛武就已经抢先一步触到球了。
5.以前；以往；过去
If someone has done somethingbefore, they have done it on a previous occasion. If someone has not done somethingbefore, they have never done it.
e.g. I've been herebefore...
我以前来过这儿。
e.g. I had met Professor Lownbefore...
我以前见过劳恩教授。
6.（直到…）才；（过了…）才
If there is a period of time or if several things are donebefore something happens, it takes that amount of time or effort for this thing to happen.
e.g. It was some timebefore the door opened in response to his ring.
他按完门铃后过了一会儿门才打开。
7.（必须先具备某一条件）才能；在…之前（必须具备某一条件）
If a particular situation has to happenbefore something else happens, this situation must happen or exist in order for the other thing to happen.
e.g. There was additional work to be donebefore all the troops would be ready.
在全军准备就绪之前，还有一些杂事必须处理。
8.（方位）在…前面，在…面前
If someone isbefore something, they are in front of it.
e.g. They drove through a tall iron gate and stoppedbefore a large white villa.
他们开车穿过一个大铁门，在一栋白色的大别墅前面停了下来。
9.（所经位置）在…前面
If you tell someone that one place is a certain distancebefore another, you mean that they will come to the first place first.
e.g. The turn is about two kilometresbefore the roundabout.
拐弯就在环岛前面约2公里处。
10.面对…（回答质询）
If you appear or comebefore an official person or group, you go there and answer questions.
before的反义词
e.g. The Governor will appearbefore the committee next Tuesday.
下周二，州长将接受委员会的质询。
11.当着…的面；在…注视之下
If something happensbefore a particular person or group, it is seen by or happens while this person or this group is present.
e.g. The game followed a colourful opening ceremonybefore a crowd of seventy-four thousand.
绚丽多彩的开幕式过后，这场比赛在74,000名观众的瞩目之下开始了。
12.摆在…面前；使面对；使面临
If you have something such as a journey, a task, or a stage of your lifebefore you, you must do it or live through it in the future.
e.g. Everyone in the room knew it was the single hardest taskbefore them...
房间里所有人都清楚，摆在他们面前的是最为艰巨的任务。
e.g. I sawbefore me an idyllic life.
展现在我眼前的是充满诗情画意的生活。
13.（重要性）超过；比…重要
When you want to say that one person or thing is more important than another, you can say that they comebefore the other person or thing.
e.g. Her husband, her children, and the Church camebefore her needs.
丈夫、孩子和教会都比她本人的需求重要。
14. before long -> see long
四、例句
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。
He always put the interests of others before his own.
他总把他人的利益放在第一位。
I'd met him once before.
我曾经见过他。
I have seen that film before.
那部电影我以前看过。
I was inspired to work harder than ever before.
我受激励比以往任何时候都更加努力地工作。
He used to get some shut-eye before the game.
他以往常常在比赛前睡一会儿。
He overlooked the contract before he signed it.
他在签字之前仔细阅读了合同。
I'll try to rush the book through before Saturday.
我会设法在星期六之前把这本书赶紧看完。
五、常用短语
六、经典引文
I am sent with broom before, To sweep the dust behind the door.
出自：Midsummer Night's Dream,ShakespeareHad he his hurts before?..Ay, on the front.
出自：Macb.Onward, Christian soldiers, Marching as to war, With the Cross of Jesus Going on before.
出自：S. Baring七、词语用法
He started five minutes ago.
He told me he had seen her a few minutes before.
英美人也有用ago，觉得语气比较生动。
When you call at the shop again this afternoon, you may be told that the book has been sold only a few minutes before.
He often forgets what he has heard only a few minutes before.
We (have) met them many times before.
When I went back to the town that I had left eight years before, everything was different.
All day, as three days before, we planted trees.
同三天前一样，我们一整天都在种树。
All day, as for three days before, we planted trees.
同以前的三天一样，我们一整天都在种树。
A few minutes before the accident she called on me.
（不含the/for）
During the few minutes before the accident she had a chat with me.
（含the）
For a few minutes before the accident she had a chat with me.
（含for）
It will not be long before they come back.
他们很快就回来了。
before的相关近义词
before的相关反义词
before的相关临近词
beforehand、befit、beforeness、beforetime、before now、before all、before tax、before day、before skip、before this、before noon、before hand