Por and Para

Por and para are frequently translated as for in English. Por has many meanings in English, while para is not as complex.

Let's look at por first:

Por refers to motivation on behalf of, or in favor of:

• por amor -- for love

to duration of time:

• por dos horas -- for two hours, por primera vez -- for the first time

or exchange:

• dos por el precio de uno -- two for the price of one

Por is also used to talk about multiplying:

• dos por tres son seis -- two times three are six

and frequency or length of time:

• voy al gimnasio dos veces por semana -- I go to the gym twice a week
  me entreno por dos horas -- I work out for two hours

Por can mean through, or by:

• andamos por las montañas --  we walk through the mountains
  viajamos por avión --  we travel by plane

or refer to something which is not yet completed:

• la fiesta está por acabar -- the party is about to finish

Por is also used to name the agent of the action in passive sentences:

• el cuadro fue robado por un ladrón conocido -- the painting was stolen by a well-known thief

Para has fewer meanings in English.

Para refers to destination:

• salió para el tren -- he left for the train

purpose:

• dos entradas para el espectáculo -- two tickets for the show

or use:

• para Ud. -- for you

Compare por and para:

• lo hice por ti -- I did it for you (for your benefit, for your sake, in your place)
  lo hice para ti -- I did it for you (I carried out the task instead of you doing it)

Using por and para correctly is often considered to be one of the most challenging aspects of Spanish for English speakers. Study the examples above, and then analyse the use of por and para in the Spanish phrases that you come across as you continue learning Spanish.