关于英文when的词性

Question

在我的词典中when有三种词性，adv，conj，pron。
但是我的词典中所给的例句比较混乱。
请问，when作为这三种词性的区别？
或者说，在一句话中，如何分辨when是副词，是连词，还是代词？
请给出例句。

Answer 1

1、[adv.]
(1)[疑问副词]什么时候，何时，在什么情况下；
用于疑问句首，如 When do you begin your classes?
(2)从前，以前；当年: When you were a child, you didn't know what it means.
(3)在……时候：His wife always complains when he smoke.
(4)[关系副词]彼时，其时:Where when he knows wrong, he doesn't admit.
2、[conj.](常用于连接两件事)
(1)什么时候：He told us when to eat.
(2)届时，在那时：He came at six, when the sun was setting.
(3) 是……的时候了：He came at a time when we needed help.
(4)当……时，在……的时候：When we are at college.
(5)每逢，每当：She smiles when you praise her.
(6)相反，而，却：To complain of one's lot when one might change it.(本来可以改变自己的命运，却自怨命苦。)
(7)既然，鉴于：How can he help when they won't let him.
3、[pron.]
什么时候(常用于定语从句)：It was in the morning, when he died.
4、[n.]
时间：When in doubt, leave out.追问

(1)He came at six, when the sun was setting.
He came at a time when we needed help.
这两句可不可以理解为when引导的从句修饰的是six和a time。这是什么类型的从句？
(2)His wife always complains when he smoke.
He came at a time when we needed help.
She smiles when you praise her.
这不都是状语从句么？您能不能详细说明一下。
(3)He came at six, when the sun was setting.
when前面加逗号是什么从句？

追答

（1）第一个是定语从句，用关系副词When引导；第二个是状语从句，不是定语从句。
（2）都是状语从句，第一句：His wife always complains 主谓都有了，when he smokes 充当时间状语，表示妻子抱怨的时间。
第二句：状语从句when we needed help表示他回来（出现）的时间。
第三句：状语从句when you praise her充当时间状语，表示她微笑的时间。
（3）when前面加逗号则是定语从句中的非限制性定语从句。