she doesn't need to/have to leave early.和 she needn't leave early.有什么区别么?
问题描述：
she doesn't need to/have to leave early.和 she needn't leave early.有什么区别么?
答
在第一个句子中need是实意动词,后接to do结构,而第二个句子中的need 是情态动词,后接动词原形.