Possessive pronouns: mine, yours, etc

Like all ‘possessive’ words and structures, mine, yours, his, hers, ours and theirs can express various ideas besides possession. They are similar to my, your, etc, but they are not determiners, and are used without following nouns. Compare:

• That’s my coat.
  That coat is mine.
• Which is your car?
  Which car is yours?

Whose can be used with or without a following noun ( (see here), (see here).

• Whose car is that?
• Whose is that car?

We do not use articles with mine, etc.

• Can I borrow your keys? I can’t find mine. (not I can’t find the mine.)

One’s cannot be used without a following noun; instead, we use one’s own.

• It’s nice to have a room of one’s own. (not … of one’s.)

Its is not normally used without a following noun.

• I’ve had my breakfast, and the dog’s had its breakfast too. (not … and the dog’s had its.)

note

For the older English form thine, (see here).