refuse v.是比较普通的用词，表示"拒绝"，含有非常坚决地、不客气地拒绝的意思。

reject v.抛弃，不采纳，主语可以是人或物，后接名词，不能接动词不定式。

He asked her to go to the movies three times, and each time she rejected him.他三次约她去看电影，但每一次都被拒绝。

deny v.否认，否定，其后可接名词，代词或that从句。

The defendant denied the accusations made against him in court.被告在法庭上否认了对他的指控。

decline v.婉言拒绝，谢绝，相当于refuse politely，主要用于拒绝有关社交活动的邀请或要求帮助的请求，后接名词或动词不定式，主语只能是人。

I invited her to join us, but she declined.我邀请她和我们在一起，可是她婉言谢绝了。