haven't和 didn't的区别

haven't和 didn't的区别 didn't和haven't什么有区别 请问I didn't see him和I haven't see him的区别 I haven‘t do 和I didn’t do 的区别. if i didn't met you和if i haven't met you 的区别是? didn't haven't didn't know,had't know和haven 't know用法有什么区别 didn't 和couldn't的区别, 请问did,didn't和have,haven't有什么区别吗?它们都是代表过去的,比如I didn't finish 请问needn't和 haven't to的区别 hasn't got 和haven't got的区别 haven't been to.和haven't gone to 的区别