Thank you for using the Jiskha Homework Help Forum. Yes, "por" and "para" can cause problems for students. See if the following explanation will help you.
THE USES OF "PARA"
1. 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."
Estudia PARA aprender (purpose) = He studies in order to learn.
Es una caja PARA dulces. (use) = It is a candy box (a box for candy).
Compré una caja DE dulces. = I bought a box of candy.
Ayer salió PARA España. (destination) = Yesterday he left for Spain.
PARA el viernes estará completo (future time) = For (By) Friday it will be complete.
PARA extranjero, habla bien el inglés. (in spite of being) = For a foreigner, he speaks English well.
2. PARA also means PARA SER.
Estudia PARA médico. = He is studying to be a doctor.
THE USES OF POR:
1. POR means "for" in the sense of "in exchange for, period or extent of time, for the sake of."
Pagó un dólar POR el cuchillo. (exchange) = He paid a dollar for the knife.
Fue al campo POR dos meses. (period) = He went to the country for two months.
Todo lo hago POR ti. (sake) = I do it all for you.
2. POR also means "for" after the verbs: ir, enviar, luchar, llamar, preguntar.
Fue (Envió, Llamó, Preguntó) POR el médico. = He went (sent, called, asked) for the doctor.
3. POR also means "during" and is often translated by "in."
POR la tarde juego al tenís. = In the afternoon I play tennis.
4. POR expresses the idea of rate and is equivalent to "per."
Ganan cincuenta dólares POR semana. = He earns fifty dollars per (a) week.
Fueron atacados POR sus enemigos. = They were attacked by their enemies.
El viajar POR avión es más rápido. = Traveling by plane is faster.
Entraron POR la ventana. = They entered through (by means of) the window.
Pasaré POR esa calle. = I'll pass along (through) that street.
NOTE: The following verbs are NOT followed by either POR or PARA, since the word "for" is part of the meaning of the verb.
buscar = to look FOR (to seek)
esperar = to wait FOR (to await)
pedir = to ask FOR (to request)
Buscaron un asiento. = They looked FOR a seat.
Quiero pedirle un favor. = I want to ask a favor of you. (I want to ask you FOR a favor.)
Esperó dos horas a su amiga. = He waited two hours for his girl friend.
Here are my two favorite examples:
a) Es un radio PARA el coche. = It's a radio FOR (that I will put into) the car. (The car gets the radio.)
b) Es un radio POR el coche. = It's a radio FOR (in exchange for) the car. (You get the radio and I get the car.)
Now when you look at your two sentences, can you see the reason why it is one or the other?
1. in order to
Yes, I was right, right?
You were right, right!
Actually, maybe in my 2nd sentence I should change por to con?
I like it better with "con."
Okay, but this other sentence of mine:
New York es una ciudad muy popular para ir de compras.
would be por then?
"in order to" so I would stay with "para." Perhaps it would depend upon "exactly" what you wish to say.
Back to the previous question = are you allowed to use "con?" If this is an exercise in using POR and PARA, it would seem you must choose one or the other?
no it isn't
P.P.S. One more thing I forgot to tell you. Look closely at the examples I gave you for PARA and POR. Often if you can substitute "A" (to, toward) it will be PARA and if you can subsitute "PORQUE" (because) it will be POR.
Salió para Madrid. = (Salió a Madrid.)
Le pagó a su vecino por el accidente. = (porque tuvo un accidente)