Question

needn't和don't need的区别和用法？

Answer 1

回答如下：
needn't (不必，不需要)中的need是情态动词，情态动词后跟动词原形; don't need中的need(需要)是行为动词，后跟名词、不定式或名词+不定式。另外，情态动词need 和行为动词need的否定和疑问形式也不一样，情态动词need只用于疑问句和否定句，而行为动词need则可用于肯定句、否定句和疑问句。例如：
We need an office.
He needs us to help him.
They need to leave here.
Do you need to stay here?
We don't need to stay here.
Need you have a rest ?
We needn't stay here.

Answer 2

don't need和needn't的区别如下：1.don't need中的need是实义动词，needn't中的need则是情态动词。needn't是情态动词的否定式，don't need是动词的否定式

Answer 3

needn't是情态动词的否定式，don't need是动词的否定式
need既可用作情态动词，也可用作实义动词。当need作情态动词时，意思是“必要，必须”，主要用于否定句（needn't）和疑问句，第三人称单数不加s，过去式不加ed；
当need作实义动词时，意思是“需要，想要”，可用于肯定句，否定句（don't need）和疑问句中，第三人称单数要加s，过去时要加ed，其后接的不定式要加to。
例：I want to go to the dentist,but you needn't go with me.
我要去看牙科医生，但你不必跟我一起去。（need作情态动词）
例：I don't need to buy a new pair of shoes.
我不需要买一双新鞋子。（need作实义动词）