hola, i see people use both of them but do you know when to use which?? also, mucho gracias and muchas gracias..


Don't quote me on it but I think ¿Que Paso? is like saying in the past tense.. like "What Happened? and ¿Que Pasa? is like saying what's wrong(present tense) or I think sometimes people say the second one when they greet close friends .. sort of like slang version of what's up?

Anyone ...?

Que pasó?=What happened?

Que pasa?=What's happening?/What's up?/What's wrong?

Both mean "what's going on?"

Technically "pasó" is preterit and "pasa" present, but they are used interchangeably in colloquial Spanish.
¿Qué pasa? - What's happening? What's going on?

¿Qué pasó? - What happened?


I don't think they can be used interchangeably.
I think so too. I cant imagine myself asking someone : ¿Qué pasó? for something thatjust happened. I mean this is used for something that already happened like you said. The proper way to use it would be : ¿Qué pasó ayer / el año pasado?

These people who talk about past vs. present tense, they understand the grammar, but they do not understand when to use the one or the other.

It's not, for the most part, about what you have just done, or done in the past, or what the person you're talking to has just done, or has done in the past---

It's about whether or not you've caught up with the person you're talking to recently. With "recently" being a hugely variable idea, of course.

And that's without getting into the whole thing where the distinction is regional, and you've got to kind of just talk to lots of people in lots of places and make lots of mistakes and learn from them before you can really get the idiom right all the time.

As with any tricky, subtle idiom, just plough ahead with whatever comes to your tongue first, and be comfortable with the fact that your words will be wrong a lot of the time. Helpful people will correct you, really helpful people will explain why, in that particular context and in that particular social setting, you should have said something very slightly different.

I don't think they can be used interchangeably.

Hi Auser and Anon, they are actually interchangable.

The use is more than anything else regional.

In Spain, when me meet somebody, we say: ¿qué pasa? Meaning, what's up?
In Mexico however, they say: ¿qué pasó? meaning the exact same thing. 

This as a form of greeting. If it is used in a sentence, one is past, one is present of something that has happened. 
En México
¡qué pasó? puede tratarse de un saludo y también de preguntar sobre algo que sucedió

¡Qué pasó Juanita! hace tiempo que no te veía.
¿Qué pasó aquí que todo está desordenado?

¡qué pasa? expresa desconcierto sobre una situación que se esté desarrollando.

Niños ¿qué pasa aquí, por qué pelean?