Possessive adjectives are used to tell what belongs to someone or to show relationships:
Like other adjectives possessive adjectives agree in number with the nouns that follow them.
Only nuestro and vuestro have different masculine and feminine endings. Su and sus can have many different meanings: his, her, its, your, or their.
The long form of possessive adjectives are used for emphasis and come after the noun: ¿Esta chaqueta es tuya? Si, es mía.