Analysis:

Singular forms of noun subject pronouns: mine (something of mine), your (something of yours), his /hers /its (something of his, her, something of it), Ben's (something of Ben).

Plural forms: ours (our things), your (your things), their (their things).

Extended data:

Nominal possessive pronoun = adjective possessive pronoun+noun

In order to avoid the repeated use of nouns, sometimes the form of "adjective subject pronoun+noun" can be replaced by "noun subject pronoun".

My bag is yellow, hers is red, his bag is blue and yours is pink.

In order to avoid reuse of bag, it can be written that My bag (adjective) is yellow, hers (noun = her bag) is red, and his (noun = his bag) is blue and? Your (noun = your bag) is pink.

Mastering these is helpful for English learning.