don't need to do 与needn't do 有什么区别?

don't need to do 与needn't do 有什么区别? need to do sth,need do sth.needn`t do sth和don`t need有什么不同! needn't do sth与don't need to do可以通用吗? don't need 和needn't 有什么区别啊? don't need 和 needn't 有什么区别? 英语don't need 和needn't有什么区别? didn't need to do 与needn't have done 的区别和相同点 have to,must,do not need,needn't的区别 needn't 和 don't need to 有什么不同? needn't和don't need to有什么区别?haven't和 don't have 有 don't have to do sth 是否等于don't need to do sth 和needn't do st 有I don‘t need to do这种形式吗或者是I needn't do形式?