A possessive determiner is a pronoun and a determiner that is used as a possessive to indicate possession. There are two types in English; dependent possessive determiners and independent possessive determiners. The dependent forms are required to be followed by a noun; the independent forms cannot be followed by a noun.
In traditional grammar, dependent determiners tend to be referred to as "possessive pronouns", and independent determiners tend to be referred to as "possessive adjectives", whereas modern grammar analyses them all as pronouns, not adjectives. All of these pronouns express the genitive case.
|Type||Dependent form||Independent form|
|First person singular||my||mine|
|first person plural||our||ours|
|Second person singular and plural||your||yours|
|Third person masculine singular||his||his|
|Third person feminine singular||her||hers|
|Third person neuter singular||its||-|
|Third person generic one||one's||-|
|Third person plural and common singular||their||theirs|
Note the rule add +s to change a dependent form into an independent form works for her-hers, their-theirs, our-ours, doesn't work for his only because his ends in -s already, and doesn't work for its and one's only because independent forms don't really exist for these.