'Por Qué' vs. 'Para Qué'

Both Phrases Typically Mean 'Why'

¿Para qué vas al dentista? (Why are you going to the dentist?). Photo by Juan Miguel Ramirez; licensed via Creative Commons.

Although both para qué and por qué in questions usually can be translated as "why," there is a subtle difference in meaning between them.

One way of thinking about the difference is that in por qué questions the speaker is seeking to know the cause of something, while para qué questions focus on the purpose or intention of something. There is an overlap, and it is often possible to substitute por qué for para qué, but not always the other way around.

Whereas the question ¿por que? might be thought of as "Why?" the question ¿para qué? might be thought of as "What for?"

Here are some examples of sentences where para qué would be a natural choice, although it wouldn't be grammatically wrong to use por qué:

  • ¿Para qué vas al dentista? Why are you going to the dentist? (For what purpose are you going to the dentist?)
  • ¿Para qué quiere pagar más? Why does he want to pay more? (For what purpose does he want to pay more?)
  • ¿Para qué estudias español? ¿Para viajar? Why do you study Spanish? For travel? (For what purpose do you study Spanish. For travel?)

See how the emphasis in these questions changes with the choice of phrase:

  • ¿Por qué murió el soldado? (What caused the soldier to die?) ¿Para qué murió el soldado? (For what purpose did the soldier die?)
  • ¿Por qué ganó la elección? (What caused her to win the election?) ¿Para qué ganó la elección? (For what purpose did she win the election?)
  • ¿Por qué es eso? (Why is that?) ¿Para qué es eso? (What's that for?)

There are many questions where it wouldn't normally make much sense to use para qué. Note how in these questions the speaker likely wants to know the cause, not the purpose, of something:

  • ¿Por qué nieva mucho más en Nueva York que en Madrid? (Why does it snow much more in New York than in Madrid?)
  • ¿Por qué hay pocos trompetistas en comparación con otros instrumentistas? (Why are there few trumpeters in comparison with other instrumentalists?)
  • ¿Por qué brilla el sol? (Why does the sun shine?)

In statements, a similar difference occurs between porque and para que, both of which express causation. The former expresses cause while para que stresses purpose.

  • Voy al dentista para que me haga mi dentadura postiza. I am going to the dentist so she can make my false teeth.
  • Todos tenemos una receta para que nuestra empresa tenga éxito. We all have a recipe for our business to have success.
  • Creo que voy a cambiar a Linux porque es gratis. I think I am going to switch to Linux because it is free.
  • Lloraron porque se sentían sólos. They cried because they felt alone.