Help with simple spanish translation?

Question

how do you ask somebody what happened to them in spanish?

like if you can tell your friend has been acting weird the last few days and you want to confront them about it how would you ask?

sort of like "what happened" in english

Answer 1

I'm not fluent in Spanish, but I do know enough to answer that.

¿Qué (se) es pasado con tú?  I don't know about the "se," I just know that it's used in French, but Spanish is more similar to Italian, where it is not used, so I wouldn't use it, but either way you'll convey your meaning.

Answer 2

Que tal? Porque te preocupes? (What's up? Why are you worried?)