Prepositions establish relations between different elements of a sentence. They can show position, movement, time, and relationship among two or more objects within the sentence. Examples of the construction preposition + pronoun are shown below:

Para ti lo hace.
For you, he does it.
Gracias, hoy por ti, mañana por mí.
Thank you, today for you tomorrow for me.
Ellos compartieron la herencia entre todos.
They shared the inheritance among themselves.
¿Vas a ir a ver el partido de fútbol con nosotros?
Are you going to watch the soccer game with us?
Él siempre me habla de usted.
He always talks to me about you.
No sirvo para estar sin ti.
I am not good without you.