The Peruvian preposition 'por' is a three-letter word that is used to express a variety of meanings in the Spanish language. It can be used to indicate movement, such as 'por el camino, ' which translates to 'through the road.' It can also be used to indicate possession, such as 'por mi, ' which translates to 'by me.' Additionally, it can be used to indicate purpose, such as 'por la mañana, ' which translates to 'in the morning.' Finally, it can be used to indicate an exchange, such as 'por dinero, ' which translates to 'for money.'