when从句的动作与主句的动作同时发生时可以用一般过去时吗？

when与连续性的或短暂性的动词连用,从句的动作与主句的动作有可能是同时发生,也可能是从句的动作发生在前,在表示两个动作同时发生时,可与WHILE互换.例如；when we were leaving,it began to rain,when引导的从句动词是leave,发生在rain之前.
While译为“在……同时”,“在…期间”,谓语动词要加延续性动词.例句：please be quiet while i ’m talking to you,.从句中是进行时时态时,一般都用while)

1. when引导的同位语从句。如：

I have no idea when he will be back. 其中idea和when he will be back都作动词have的宾语, when he will be back是idea的具体内容。

2. when引导的非限制性定语从句和被修饰先行词的短语隔开的when引导的限制性定语从句。如：

They came to China in 1970s, when China was not open to the outside world.

这是一个含有非限制性定语从句的主从复合句，when引导的是一个非限制性定语从句，该句修饰1970s。再如：

Do you still remember that evening ten years ago when I came to your house?

ten years ago插在先行词evening和定语从句when I came to your house之间，对正确判断when I came to your house产生干扰。有时，为了平衡句子，也会出现先行词和定语从句分隔的现象。

3. 提供信息的when分句中when往往表示and then, and just then, and at that time, and suddenly等意思。它充当并列连词，连接两个并列分句，提供与前文并列的信息。这种用法的when分句一般位于句末，易误判为时间状语从句。如：

I was walking along the road when suddenly someone cried for help.

when的这种结构译成汉语时, when分句不能提前；否则，意义和逻辑上行不通。