As with English, most questions in Portuguese begin with a word such as who, what, where, when, how, why, etc.
 

Aonde?	Where?
Cade?	Where is?
Como?	How?
De quem?	Whose?
Onde?	Where?
Pode?	Can you?
Por que não?	Why not?
Porque?  ++	Why?
Quais?	What?
Qual?	Which?/What?
Quando?	When?
Quanto?	How much?
Quantos?	How many?
Que? ++	What?/Which?
Quem?	Who?

++ When que and porque are used alone, a circumflex (^) is added to the e (e.g. quê; porquê). Additionally, que is often used in interjections and denotes a great quantity or "how", for example, que bonita! = how pretty!