This is a really important preposition, very common to use in Spanish. Many students can confused about the use of para with por, because they both are translate as “for”, though they have different meanings.
Here is a list of situations when you must use para instead of por.
For frequency and velocity.
With the meaning of “along” or “through”.
With the meaning of “on behalf of”.
With means of communication.
With the meaning of “because of”.
For exchanges and sales.
To express actions that still need to be completed.
To express duration in time.
Here is a list of situations when you must use por instead of para.
With the meaning of “in order to”.
With the meaning of “intended for”.
When you want to specify a future moment in time.
With the meaning of “to be about to”.