英语

(1)He fell asleep before I could take off his clothes.

(2)We arrived there before it atarted to rain.

(3)The holiday came to the end befor I knew it.

(4)He almost knocked me down before he saw me.

2.主句谓语动词强调动词的迟缓性，只用before，常伴有时间段状语或时间段暗示。例：

(1)It was quite some time before he found the elephant at all.

(2)We had walked a long way before we found some water.

(3)We had sailed for two days before we saw the land.

(4)The fire lasted about four hours before the firefighters could

countrol it.

(5)It was midnight before my brother came home.

(6)It was three months before they met 3.如果强调从句谓语动作未发生，就发生主句谓语动作，只用before。常译为“未及”，

“不”或“不等 就”。例：

(1)We can leave early in the morning before it gets too hot.

(2)I must write it down before I forget it.

(3)We do want to buy something now before prices go up.

4.表“与其说 倒不如”，“与其 毋宁 ”只用before。例：

(1)I would give up my job before I'd agree to be dismissed.

(2)He will die of hunger before he will steal.

5.在某些特定句型中用before。例如：

(1)It was not long before the whole country rose up.

(2)It will probably not be long before they understand each other.

三、下列情况一般区别用until。

1.主句是持续性谓语动词时，肯定、否定都可以，但意义完全不同。肯定表动作终止，而否

定表动作开始。例如：

(1)We discussed the problem until/before he came back.我们一直讨论到他回来。

(2)We didn't discuss the problem until he came back.我们一直等到他回来后才讨论问

题。

2.not until句型尽管在某些情况下可与before互换用，但在强调句中一般仍用until。

例如：

例如：

(1)It was not until he told me that I knew it.

(2)It was not until he finished his homework that he went home.

before 的用法归纳

before 可以和过去完成时连接。

一。 过去完成时主要有以下几点用法：

1. 表示过去某一时间或动作之前已经发生或完成的动作或存在的状态。句中常用by，

before， when， until等词引导的时间状语。它是以过去某一时间为起点，所以过去完成时

是一个相对的时态，表示的是“过去的过去”。只有和过去某时间或某动作相比较时才能用到

它。例如：

Most of the guests had left when he arrived at the party. 当他到达晚会时，他发现大多数客人已

经离开了。