Here's a summary of the difference:
The uses for para: (often "a" can substitute)
1. Para means "for" in the sense of purpose, use, destination , for (by) a time in the future, considering that (sin spite of the fact that). It is also translated by "in order to, to, by."
2. Para also means "para ser" (as in a career)
The uses for por: "porque" can substitute)
1. Por means "for" in the sense of in exchange for, eriod or extent of time, for the sake of
2. Por also means "for" after certain verbs: ir, enviar, luchar, llamar, pretuntar
3. Por also means during" and is often translated by "in"
4. Por expresses the idea of rate and is equivalent to "per."
5. In addition, por also means "by, through, along"
NOTE: The following verbs use neither "por" nor "para" because 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)
Now, you have chosen well, but can you find the reason?
Thanks so much for the explanation! I understand the reason now.
Thank you so much! It looks like you have helped 2 people :) thank you! I really appreciate the explanation.