The possessive pronoun is translated as 'my' 'your' 'his' 'their' etc in English, and can be easily confused with the personal pronoun in Latin - especially with regards to 'ego, me' etc (the personal pronoun I/me) and 'meus, mea, meum' etc (the possessive pronoun for the 1st person). The main difference is that the personal pronouns function as nouns in a sentence - with their own paradigms that must therefore be learned - and that possessive pronouns are adjectives, and generally decline like an adjective in the same style as 'bonus, bona, bonum'.