什么是 “When Be Doing”?
“When be doing” 是英语中一种常见的结构,通常出现在 when 引导的时间状语从句中,表示“当某人正在做某事的时候……”。这里的 “be doing” 是现在进行时(或过去进行时)的形式。
例如:
When I was walking home, it started to rain.
(当我正在走路回家时,开始下雨了。)
语法规则
- 主句 + when + 主语 + was/were + 动词-ing:用于描述过去某一时刻正在进行的动作被另一个动作打断。
- “When” 引导的从句通常使用 过去进行时,而主句常用 一般过去时。
- 也可以用于现在时态,但较少见,多用于叙述故事或假设场景。
经典例句
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When she was cooking, the phone rang.
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I met an old friend when I was traveling in Japan.
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When they were playing soccer, it began to thunder.
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Be careful when you are crossing the street.
常见误区
❌ 错误:When I did my homework, my mom came in.
✅ 正确:When I was doing my homework, my mom came in.
说明:强调“正在做作业”这个持续动作时,应使用进行时。
小测验(互动练习)
试着完成下面的句子(答案在控制台输出):
1. When he was driving, a dog ran across the road.
2. We were watching TV when the lights went out.