How to say why in Spanish

The Spanish word for why is por qué.
How to pronounce por qué in Spanish:
Click to hear the pronunciation of por qué  
Examples of por qué in Spanish:
¿ Y tú, por qué te ríes ?
And you, why are you laughing?

¿Por qué debería yo contratarlo?
Why should I hire you?

¿Por qué aprendes chino?
Why are you learning Chinese?

Do you know another example that uses why in Spanish? Please tell us where you read or heard it (including the quote, if possible).