- porque (Portugal)
- por quê (used in the end of sentences, or as a sentence of its own)
- pq (Internet slang used as an abbreviation for 'por que' and all its variants)
por que (not comparable)
- (Brazil, introducing a question) why, what for, for what reason
Por que são os céus azuis?
- Why are the skies blue?
- (Brazil, introducing a question, uncommon) by what, through what, via what
Por que caminho seguir?
- What way should we follow?