Question

Tom was working in the garden while I was sitting in the sun.这个句子中的while能不能用when代替呢？

Answer 1

在这个句子里，习惯用法是用while,不用when。它们的主要区别是：
1.when是at or during the time that, 既指时间点，也可指一段时间，while是during the time that，只指一段时间，因此when引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而while从句中的动词必须是延续性动词。

2.when 说明从句的动作和主句的动作可以是同时，也可以是先后发生；while 则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。

3.由when引导的时间状语从句，主句用过去进行时，从句应用一般过去时；如果从句和主句的动作同时发生，两句都用过去进行时的时候，多用while引导，如：

a. When the teacher came in, we were talking.

当此句改变主从句的位置时，则为：

While we were talking, the teacher came in.

b. They were singing while we were dancing.

追问

1. When the teacher came in, we were talking.能不能改为when we were talking,the teacher came in?这样有没有区别？
2.既然while强调两个动作同时进行，为什么不是这样呢？While we were talking, the teacher was coming.

追答

1.When the teacher came in, we were talking，这句话语法错误，
正确的应该是:when we were talking,the teacher came in.
2.While we were talking, the teacher was coming.也是可以的

追问

When the teacher came in, we were talking,这句话能不能详细的一点解答呢？

Answer 2

不能吧，when表示正在做某事的时候突然发生了另一件事，是有一点先后顺序的，比如你正在看书的时候你妈妈进来了：my mom came in when I was reading. 而 while则完全没有先后顺序，是同时正在发生的

Answer 3

不能