If you mean the Spanish ''por'' as in the English ''for'', its για (gia).
por kay (spelt 'por que') is simply "why"; e.g. 'por que no?', "why not?"
"¿Por qué [k] no?" It means, "Why not?"
es por ti = is for you
por auto = by car
"why not?"
por la vida= for life
"Loca por ti" means crazy for you.
"¿Por qué corres?" means "Why do you run?"
Depending on context, it can mean several things. For, by, through. It is also used in many idiomatic expressions that are taken as a whole, por aqui, por favor, etc.
For always
please
For your