Ask who, what, where, when, why, and how — plus the words that join sentences.

• o que / o quêwhatwhat | O que é isto? = What is this? ("o quê" stands alone or ends a sentence: Fizeste o quê? = You did what?)
• quemwhowho | Quem é aquele rapaz? = Who is that boy?
• ondewherewhere | Onde está o teu carro? = Where is your car?
• aondewhere (to), with movementwhere (to), with movement | Aonde vais? = Where are you going (to)?
• quandowhenwhen | Quando chegas? = When do you arrive?
• porquê / porque / por quewhywhy | Porque estás triste? = Why are you sad? Standalone or at the end use "porquê": Porquê? = Why? Before a noun use two words: Por que razão? = For what reason?
• comohowhow | Como estás? = How are you?
• quanto / quantahow muchhow much | Quanto custa? = How much does it cost? (agrees in gender: Quanta água? = How much water?)
• quantos / quantashow manyhow many | Quantos anos tens? = How old are you? (lit. How many years do you have?); Quantas pessoas? = How many people?
• qual / quaiswhich, which onewhich, which one | Qual preferes? = Which one do you prefer? (plural: Quais são os teus? = Which ones are yours?)
• que + substantivowhich/what (before a noun)which/what (before a noun) | Que cor preferes? = Which/what colour do you prefer?
• a que horasat what timeat what time | A que horas começa o filme? = At what time does the film start?
• eandand | Eu e tu. = You and I.
• ouoror | Chá ou café? = Tea or coffee?
• masbutbut | Quero ir, mas estou cansado. = I want to go, but I'm tired.
• porque (causa)becausebecause | Fico em casa porque está a chover. = I'm staying home because it's raining. (Note: as 'because' it is always one word, distinct from the standalone interrogative 'porquê'.)
• tambémalso, tooalso, too | Eu também quero. = I want it too.
• entãoso, thenso, then | Não há leite, então bebo água. = There's no milk, so I'll drink water.