何なんなの

expression

what's up with ...?; what the hell?; what was that?

Colloquial expression used to express surprise, irritation, or demand for explanation. Often rhetorical or emphatic. Can be directed at a situation or a person's behavior.

• 急きゅうに呼よび出だして、何なんなの？

  Calling me out suddenly, what's up with that?

• さっきの音おと、何なんなの？

  What was that sound just now?