Spanish has two prepositions that often get translated as "for" in English: por and para. These words aren't interchangeable and can cause some confusion when used incorrectly.
In the two examples "Trabajo por Pedro" and "Trabajo para Pedro," both would be translated as "I work for Pedro." But in Spanish, they mean two different things. The first means "I work instead of, or on behalf of, Pedro," meaning I'm taking over his responsibilities. The second means that I actually work for Pedro, making him my boss.
One way to remember when to use por or para is to think of por as "fluid." It focuses on expressing movement through time or space. Para is more "fixed." It's more focused on conveying destinations or end points. In some countries, para is sometimes shortened to "pa" when spoken. For example, someone might say "pa' que" instead of "para que."
Here are some more specific ways to distinguish between the two.
Movement (through, around, along, by)
Viajé por Francia y España. I traveled through France and Spain.
Pagué 5 euros por esta cerveza. I paid five euros for this beer.
Duration (for, per)
Viajé por does meses. I traveled for two months.
Reason (because of, on behalf of, by means of)
Por tu culpa llegué tarde al trabajo. Because of your fault I arrived to work late.
Salgo para Cuba mañana. I leave for Cuba tomorrow.
Este regalo es para Luis. This gift is for Luis.
La tarea es para el martes. The homework is for Tuesday.
Goal (in order to)
Estudio español para poder hablar con mis amigos. I study Spanish in order to be able to speak with my friends.
Por and para are also used in common phrases. It's best to memorize these.
Por adelantado (in advance)
Por ahora (for now)
Por allí/allá (over there, that way)
Por aqui/acá (around here, this way)
Por casualidad (by chance)
Por ciento (percent)
Por cierto (certainly)
Por dentro (inside)
Por desgracia (unfortunately)
Por ejemplo (for example)
Por eso (therefore, that's why)
Por favor (please)
Por fin (finally)
Por lo general (generally)
Por lo que veo (from what I can see)
Por medio de (by means of)
Por mi parte (as for me)
Por lo menos (at least)
Por ningún lado (nowhere)
Por otra lado (on the other hand)
Por otra parte (on the other hand)
Por primera vez (for the first time)
Por separado (separately)
Por suerte (fortunately)
Por supuesto (of course)
Por lo tanto (consequently)
Por todas partes (everywhere)
Por todos lados (everywhere, on all sides)
Por último (lastly)
Para nada (for nothing; at all)
Para siempre (forever)
It may seem confusing at first, but por and para will become second nature the more you practice. As with all Spanish grammar lessons, it's a good idea to mix in listening and reading with your more focused lessons. Check out our Spanish Native Resource Guide for resources that will help you incorporate the language into your daily life.