在你问某人发生了什么事或遇到了什么问题的时候就可以说 "what's up?"。

例句

What's up? I came to your house to party and everybody is sitting around looking sad.

What's up with Lauren? She's been acting in a very strange way.

请注意

在美式英语里，"what's up?" 是一个常见的打招呼用语，意思是"你好吗？"

例句

What's up, Frank? I haven't seen you in ages.