英语语法: 容易混淆的单词as（when while）

As, when or while?

容易混淆的单词as, when, while?

现在的英语语法As，when和while是连词。在某些用法中，as、when和while的含义是相同的，但它们的含义也略有不同。我们用它们来介绍从句。我们可以使用as，when和while来表示“在这段时间内”，来连接同时发生的两个事件：

Another coach-load of people arrived as we were leaving.我们离开的时候又来了一车人。

我们经常把它们与过去连用来指代背景事件：

When the men were out working in the field, I helped with milking the cows, feeding the calves and the pigs.当男人们在田里干活的时候，我帮忙挤奶，喂牛犊和猪。While he was working, he often listened to music. 他工作时经常听音乐。

我们可以在主句之前或之后加上as、when和while。当它们出现在主子句之前时，我们使用逗号：

1. As she was leaving the court, a crowd of photographers gathered around her. (before the main clause, followed by a comma)当她离开球场时，一群摄影师聚集在她周围。（在主子句之前，后跟逗号）2. Steven was very unhappy when things weren’t going well for him.3. Lucy came into the room while he was waiting.露西在房间里等他。

As

我们可以用as来讲述两个同时发生的事件。在as之后，我们可以使用简单的或连续的动词形式。进行时强调发生在另一动作进行过程中的动作：

1. As she walked to the door, she thanked them for a lovely dinner.当她走到门口时，她感谢他们做了一顿丰盛的晚餐。2. As they were signing the contract, they noticed that a page was missing.他们在签合同时注意到少了一页。

When

我们可以使用when来引入在较长活动或事件的中间发生的单个已完成事件。在这些情况下，我们通常在主句中使用连续动词来描述背景事件：

He was walking back to his flat when he heard an explosion.当听到爆炸声时他正往公寓走。

根据上下文内容，when的意思可以是“after”或“at sample time”。

比较

While and as

我们可以用while或as来谈论同时发生的两个较长的事件或活动。我们可以使用简单的或连续的动词形式：

1. We spent long evenings talking in my sitting-room while he played the music he had chosen and explained his ideas.我们在我的客厅聊了很长时间，他一边演奏音乐，一边解释他的想法。2. We were lying on the beach sunbathing as they were playing volleyball.他们打排球时，我们躺在沙滩上晒日光浴。

When and while

我们可以在没有动词的时候使用when和 while，或者没有主语+辅助动词be：

1. Go past the village signpost and you get to a church. When there, take the next turning right. (formal)过了村里的路标，你就到了教堂。到那儿后，在下一个路口右转。（正式）2. He read his book while waiting for the bus. (while he was waiting)他在等公共汽车时看书。（在他等待的时候）

备注:

as的特殊情况:

We ate our sandwiches as we walked around the park.我们边逛公园边吃三明治。

错误用法: … as walking around the park.