¿Que or Cual es tu problema?
Here is a nice link. Mis mejores deseos.
Very good and necessary discussion !
Considering that "qué" is supposed to solicit a definition whereas "cuál" asks the respondent to limit the answer to one of possible many one might say "qué" is the way to go.
¿Qué es eso? - What is that ? ¿Para que es eso? -What is that for ?
¿Qué es su nombre? - Mi nombre es la palabra que la gente usa cuando me llama.
¿Cuál es tu nombre? - Mi nombre is Alejandro.
But I have to admit this stuff does not make a lot of sense to me.The above definition directly clashes with
¿Qué día es hoy?
I mean are they telling me that I'm trying to ask the person what a day is ? Not really. Rather I'm trying to have the person limit their response to one of exactly 7 possible answers - should be classic "cuál" but it isn't. That same way I could argue that "What's your problem?" asks the person to limit their response to one of a huge number of possible problems that exist in the world. Same with:
¿Qué hora es? According to the definition I'm trying to ask the person what time it is and they might say "It's the right time" or something like that.
I just looked back at my pronoun book and they say
¿Cuál es tu razón por esto? - What is your reason for this ?
Judging by that the answer to your question would be Cuál. It seems that a lot of these rules keep clashing with these 2 words.
eRagi, your question basically is this. Does "What's your problem ?"
A: Try to solicit a definition/explanation of what this person's problem is ? In other words explain the problem itself.
B : Try to have the person pick a problem out of a vast number of possible problems that exist in the world ?
I'd be interested in some answers myself.