The word "why" in Spanish is "por qué" when used in questions.

Examples:

• Why are you here? - ¿Por qué estás aquí?
• Why did you do that? - ¿Por qué hiciste eso?

Note:

• "Por qué" (two words) is used in questions and means "why."
• "Porque" (one word) means "because" and is used in answers.
• "Porqué" (one word with accent) means "the reason" (a noun).
• "Por que" (two words, no accent) is less common and used in specific grammatical contexts.

If you want, I can give you more examples or explanations!