It's a possessive pronoun. From the 'Tips' section in 'Possessions': "In Italian an article is almost always mandatory before a possessive pronoun. The exceptions are: It's not used before close family members, in the singular and not modified, e.g. "mio padre" (my father), unless the possessive is "loro" (in which case the article is needed). It's optional when the possessive adjective is alone following a form of "essere," e.g. "è mio" (it's mine). It's not used in a small number of set phrases, e.g. "casa mia" (my home)" Hope that helps.