"The girl asked for water."
Translation:Ela pediu por água.
Going by http://www.learn-portuguese-with-rafa.com/por-and-para-in-portuguese.html especially, "Vou comprar um bolo para a Maria" - "I'm going to buy a cake for Maria" = FOR = PURPOSE." then para still makes more sense to me.
There was someone who said as a simple generalisation por = for and para = to. Do you think that's fair, or are there too many exceptions to use that as a guide?
"Para" is always the destination/goal/objective/the planned action. (If there are exceptions, they are few).
Por is the complicated one. It can be:
- Foi por isso que eu voltei = It was because of it that I came back
- Fiz por amor = I did it for love (because of love)
A mix between cause and thing you want to "promote/benefit"
- Ele luta pela comunidade = He fights for the community (to help it, to keep it alive, to benefit it)
- Tudo por você = All for you / All because of you (it's not an accusation, but the subject wants to see "you" well - see further explanation below).
Means through which things are done:
- Ela me falou por telefone = She told me by the phone
- Por meio de ... = by means of...
On behalf of
- Eu falo por ele = I speak on behalf of him
Further explanation about "the cause/accusation".
There is the expression "por causa de", which means because of. In that sentence I commented above, the difference would be:
- Tudo por você = All for you (In this, "você" inspires the subject and he wants to do everything for "you").
- Tudo por causa de você = All because of you (this one can be more like an accusation, all that happened was because of "you")
This "ask for" case is tricky, now that I think of it. One could think that "water" is the goal/objective. But then I remember that the motion is not from her to the water, but from the water towards her.
- To say "ela pede para água" is nonsense.
- But you can say "pede para sair" (asks to get out). Here, sair is the objective, the planned action.
The same would apply to "esperar".
- Ele espera por um milagre (he waits for a miracle - to come to him)
- Ele espera para fazer de novo (he waits to do it again)
Foi por isso que eu voltei = I came back because of it.
Foi para isso que eu voltei = I came back for that (as the planned acion, came back to do that)
Tudo pela comunidade = All for/because of the community
Tudo para a comunidade = All for/to the community (the community is receiving the things being given. Motion towards the community)
Eu falo por ela = I speak on behalf of her
Eu falo para ela = I speak to her/I tell her
I think both "por" and "para" can be translated as "for" sometimes so that simple rule doesn't work.
As I understand it, the sentence "I'm going to buy a cake for Maria" can be written as either "Vou comprar um bolo pela Maria" and "Vou comprar um bolo para a Maria" but they don't mean quite the same thing. The difference is that in the "por" version we know you're buying the cake on her behalf (perhaps she couldn't make it to the bakery to buy it herself) and in the "para" version all we know is that you are going to give the cake to her (as a present perhaps).
[Oops - I just posted this and then found Daniel had produced a comprehensive overview.]