It's mine / yours / ours — possessive pronouns
1. It's my phone.
2. It's mine.
3. The book is mine.
In sentence #1, we use the pronoun "my" together with the noun "phone".
In sentences #2 and #3, there is no noun because we don't want to repeat it.
You have to remember the forms of these possessive pronouns:
|Pronoun||Possessive adjective||Possessive pronoun||Examples|
|I||my||mine||It's my phone.||→ It's mine.|
|you||your||yours||It's your phone.||→ It's yours.|
|he||his||his||It's his phone.||→ It's his.|
|she||her||hers||It's her phone.||→ It's hers.|
|we||our||ours||It's our phone.||→ It's ours.|
|they||their||theirs||It's their phone.||→ It's theirs.|
Is it your hat? Yes, it's mine.
Is it our problem? No, it's theirs.
That's not my pencil. It's yours.
I show her my photos, and she shows me hers.
Let's learn questions with "whose".
Whose … is this? / Whose ... are these? = Who is the owner? Whom does this thing belong to?
Whose car is this? It's mine.
Whose tennis rackets are these? They're Kate's.
Whose desk is this? It's his.