1. I know this set can be tricky
Por and Para means for, but we have to use it correctly, don't we?
(Gratitude or apology),(Multiplication and division), (Velocity, frequency and proportion), ("Through," "Along," "By" or "In the area of"), (Exchange, including sales), ("On behalf of,"or "In favor of"), (Length of time), (General time "during"), (Means of communication or transportation), (Cause or reason), ("Estar por" means to be in the mood, or inclined to do something)(Passive constructions)
(Destination), (Use or purpose of a thing), (Recipient), (Deadline), (Contrast), ("Estar para" an action to be completed), (To work for),