I'll send this to our Spanish expert, SraJMcGinn.
And what do YOU say? Here are some "rules" for por vs para:
THE USES OF POR AND PARA:
PARA means: for, in the sense of purpose, use, destination, for (by) a time in the future, considering that (in spite of the fact that). It is also translated: in order to, to, by. Many times you an substitute the word "a" (to, toward, and not the Personal "a") instead of "para."
Para also means "Para ser"
POR means: for, in the sense of in exchange for, period or extent of time, for the sake of.
Por also means: for, after the verbs: ir, enviar, luchar, llamar, preguntar
Plr also means: during and is often translated by in.
Por expresses the idea of rate and is equivalent to "per."
Por also means by, through, along
Usually you can substitute "porque" for "por"
If you would like lots of exercises where you must choose POR or PARA, let me know and I'll be happy to type them out for you. That is actually the BEST way to be sure you DO understand the differences between the 2 words.
***The following verbs are not followed by "por" or "para" because the word "for" is part of the meaning of the verb. They are:
buscar = to look FOR, to seek
esperar = to wait FOR
buscar, to await
pedir = to ask FOR, to request
Often for para, you can substitute "a."