The Difference between Por and Para

Let me see if I can teach you the difference between por and para in as little time as possible:

The word por is used in the following circumstances:

1)to mean "through", "by", or "around"
Fui por la puerta para salir. I went through the door to exit.

2)to mean "in exchange for"
Pagué 15 dólares por este suéter. I paid 15 dollars for this sweater.

3)to mean duration
He estado en Colombia por tres días. I've been in Colombia for 3 days.

The preposition para is used in the following circumstances:

1)to mean "for"
Este libro es para ti. This book is for you.

2)to mean "in order to..."
Necesito ir al mercado para comprar unas verduras. I need to go to the market (in order) to buy some vegetables.

3)to express "by" a certain time
Entrego este papel para el 15 de octubre. I will turn this paper in by October 15.

Hope this helps! Any questions or comments? Post them below....