1. Basically, «POR» is used to express movement through time or space. This can be:
1.1 A physical transition such as traveling
Viajé por América. (I traveled through America.)
1.2 An exchange of objects
Pagué 50€ por este bolso. (I paid 50€ in exchange for this handbag.)
1.3 A duration of time
Tengo que trabajar por doce horas hoy. (I need to work for twelve hours today.)
1.4 A motivation/reason for doing something
Aprendí español por mi trabajo. (I learned Spanish because of my job.)
2. And «PARA» is generally used to convey destinations or endpoints. These can be:
2.1 Physical locations
Salgo para Nueva York mañana. (I leave for New York tomorrow.)
2.2 People (recipients)
Este regalo es para mi novia. (This gift is for my girlfriend.)
2.3 Deadlines
El jefe necesita el informe para mañana. (The boss needs the report for tomorrow.)
2.4 Goals
Ahorra mucho para comprar una casa. (He saves a lot in order to buy a house.)
3. There are also many expressions that are used with por and para. Some of the most common are:
| para siempre | forever | | por ejemplo | for example | |
para variar | just for a change | | por favor | please |
para que | so that/in order that | | por ciento | percent |
| | | por supuesto | of course |
| | | ¿por qué? | why? |
| | | por fin | finally |