when在英语里有三种词性

Question

如题所述

Answer 1

when在英语里有三种词性：

特殊疑问词，“什么时候”，后面跟一般疑问句语序。如：
When were you born?
When will the class begin?
When do you start work and finish work?

从属连接词，“当什么时候”，引导时间状语从句，后接陈述句的语序，如：
He always helps me when I am in trouble.
When my dad came back, I was watching TV.

缩合连接副词，引导名词性从句。
This was when I was born.
Do you know when the class will begin?
I don't know when they will achieve the goal.
此外，疑问副词when后面加动词不定式to do（注意，when后面没有接动名词doing的用法），可以作句子的主语，表语、宾语等，如：
I don't know when to use the sentence pattern.
When to go is a problem.
The problem is when to begin the class.