Are "para que" and "porque" interchangeable when meaning "so that"?
Title has it all.
3 Answers
The difference is really the essence of por vs para.
Por for a past / motivating reason (I often visualize looking behind you when it comes to por).
Para for a future purpose (again, try visualizing looking forward with para).
porque - for the reason that
para que - with the purpose that
Lo compré porque era barato. I bought it because it was cheap. (reason that led up to it)
Lo compré para que la niña se sienta feliz. I bought it so that the girl will feel happy. (future purpose)
(carrying on Aeribel's theme jeje)
I'll put an example.
I bought a toy so that my niece has something to play with while I'm babysitting her
Compré un juguete para que mi sobrina tenga algo con lo que jugar mientras la estoy cuidando.
Compré un juguete porque mi.... This is wrong. It makes no sense, so you would have to change the sentence to: Compré un juguete porque estoy cuidando a mi sobrina y quiero que tenga algo con lo que jugar. (I bought a toy because I am babysitting my niece and I want her to have something to play with)
"Para que" can be used to say something like: "in order to" or "so that" since para in this particular scenario represents a reason, the word "que" added to the first one would mean that it is specifying what the purpouse is.
I don't know if I'm making myself clear since I am a spanish speaker but what I'm trying to say is that the concept of the two words when they are together aims for a reason and purpouse kind of situation.
Para que algo suceda would traslate to "in order for something to happen" which would be the effect of an action and then you would have to specify the cause of such effect but it can also be translated into "so that something will happen" also being an effect of an action but mentioned after the cause has been explained.