"what's happen"的"'s"代表什么

"what's happen"的"'s"代表什么 what's happen的S怎样理解 What happen...What's the matter ...What's wrong .的用法～后面+什么? What's happen? what's happen what's happen还是what happen? what's going to happen what happen to与what’s wrong的区别 请问：happen的用法.eg:what happened,what's happen的区别 what's up 和 what happen这两个都是发生什么事情的意思吗 有什么区别 swwety,what 's happen to you? What happen's in vegas,stay vegas.