Long Form Possessive Pronouns

Possessive adjectives in Spanish, like those of English, are a way of indicating who owns or is in possession of something. Their use is straightforward, although they (like other adjectives) must match the nouns they modify in both number and gender.

Spanish has two forms of possessive adjectives, a short form that is used before nouns, and a long form that is used after nouns.

mío, mía,
míos, mías		 my, of mine Son libros míos.
(They are my books. They are books of mine.)
tuyo, tuya,
tuyos, tuyas		 your (singular familiar), of yours Prefiero la casa tuya.
(I prefer your house. I prefer the house of yours.)
suyo, suya,
suyos, suyas		 your (singular formal), its, his, her, of yours, of his, of hers Voy a la oficina suya.
(I am going to his/her/your office. I am going to the office of his/hers/yours.)
nuestro, nuestra, nuestros, nuestras our, of ours Es un coche nuestro.
(It is our car. It is a car of ours.)
vuestro, vuestra, vuestros, vuestras your (plural familiar), of yours ¿Dónde están los hijos vuestros?
(Where are your children? Where are the children of yours?)
suyo, suya,
suyos, suyas		 your (plural formal), their, of theirs Voy a la oficina suya.
(I am going to your/their office. I am going to the office of yours/theirs.)

Note that the possessive adjectives vary by number and gender.
The change is with the nouns they modify, not with the person(s) who own or possess the object.

Es un amigo tuyo. (He is a friend of yours.) Es una amiga tuya. (She is a friend of yours.) Son unos amigos tuyos. (They are some friends of yours.) Son unas amigas tuyas. (They are some friends of yours.)

Choice of possessive form:
Generally speaking, there is little or no difference in meaning between the long and short forms of the possessive.
Most often, you'd use the long form as the equivalent of "of mine," "of yours," etc., in English, although (as in English) they are usually interchangeable in meaning.

The short form is more common, and in some cases, the long form can be somewhat awkward
or have a slight "literary" flavor, although it is used in informal speech as well.