How to use " por " y "para" in Spanish
Por is used to talk about movement, modes and means of travel and communication, exchanges, duration, and motivation, among other things. Examples: La contacté por correo= I contacted her by mail.
Te cambio mi manzana por tu sandwich. =I'll trade you my apple for your sandwich.
Para is used to talk about destinations, recipients, deadlines, and goals. Check out the following examples of these common uses of para.:
Salgo para Chile mañana. =I leave for Chile tomorrow.
Este regalo es para Adela. =This gift is for Adela.
Necesito la presentación para el viernes. =I need the presentation by Friday.