The mall is a really fun place to go.为什么用fun而不用funny?fun是名词、

fun也有形容词性的意思,有趣的,providing enjoyment; pleasantly entertaining; "an amusing speaker"; "a diverting story"; "a fun thing to do"；funny则是滑稽的,常常是因为not as expected而显得可笑的
再问： 他们之间只是贬义和褒义的区别？