请教needn't have ,don't have to是什么意思?

问题描述：

请教needn't have ,don't have to是什么意思?
You needn't have waken me up,I (don't have to)go to work today.
1.请问needn't have 是什么意思?don't have to是什么意思?
2.这里为什么不能用haven't to,而要用don't have to?

1个回答分类：英语 2014-11-20