Spanish Grammar/Por

Por is used…

when expressing gratitude or apologizing

e.g. Lo siento por lo que dije. – I'm sorry for what I said.

e.g. Gracias por venir. – Thank you for coming.

for multiplication

e.g. Dos por cinco son diez. – Two times five is ten.

when talking about velocity, frequency, or proportion

e.g. Como tres veces por día. – I eat three times a day.

e.g. Conduzco 60 millas por hora. – I drive 60 miles per hour.

when saying "through," "along," "by," or "in the area of"

e.g. Caminamos por el parque. – We walk through/in the area of the park.

when discussing something exchanged or sold

e.g. Te doy tres dólares por el sándwich. – I'll give you three dollars for the sandwich.

to express "on behalf of" or "in favor of"

e.g. No voté por nadie.

to express a length of time

e.g. Hoy hice deporte por una hora y media hoy. – I exercised for an hour and a half today.

when referring to a nonspecific time, to mean "during"

e.g. Cocino mucho por el fin de semana.

e.g. Trabajo por la tarde.

to refer to means of communication or transportation

e.g. Hablo con mi madre por el teléfono. – I talk to my mom on the phone.

e.g. Normalmente viajo por coche pero esta vez yo voy por avión. – Normally I travel by car but this time I'm going by plane.

in cases of mistaken identity, or meaning "to be seen as"

e.g. Me tienen por loco. – They take me for crazy.

when explaining the purpose of an errand (with ir, venir, pasar, mandar, volver, and preguntar)

e.g. Paso por ti a las ocho. – I'll come by for you at eight o'clock.

expression: por + infinitive – expresses an incomplete action

e.g. La cena está por cocinar. – Dinner has yet to be cooked.

to express cause or reason

e.g. Murió por falta de agua. – He died due to a lack of water.

                e.g. Hoy estoy resfriada, y por eso no fui a clase.- I have a cold today, so I didn't go to class.

expression: estar + por – to be in the mood, to be inclined to do something

e.g. Estoy por salir. – I feel like going out.

to indicate agent in passive constructions

e.g. El autobús está conducido por el conductor.

to denote authorship

e.g. Por Julio Iglesias- by Julio Iglesias

Por is used in many common expressions and phrases. Here are some good examples: