In portuguese, when would you use 'O que' and 'Qual'?

Question

I know that 'o que' means "what" and the other one means "which", but when would you specifically use one over the other?

For example, in "Cual é o seu nome?" why is 'cual' used instead of 'o que'?

oops! i meant 'Qual'...

Answer 1

O que, que and qual have sometimes the same meaning and can easily be confused.
O que and qual are always followed by a subject pronoun (você) and a verb while que is always followed by a noun. Qual usually implies a choice.
O que is usually followed by é que (ever), but it can be omitted without altering the meaning of the phrase. É que is normally used to emphasize.

Answer 2

Well I usually use qual whenever I have a decision to make... (I am in Brazil right now studying for the year.) Like: Qual tipo de café você prefeiro? (What type of coffee do you prefer?)... And I use que mostly in Que foi? (What happened?)... Sorry if this doesn´t help. I mostly write direct translations... (And I didn´t know how much Portuguese you knew so I added translations... If you would like I could have my mother explain it but she only speaks Portuguese...)