hers theirs
Note that its cannot be used as a possessive pronoun.
typical use
1.108 You use possessive pronouns when you are talking about the same type of thing that has just been mentioned but want to show that it belongs to someone else.
For example, in the sentence Jane showed them her passport, then Richard showed them his, his refers to a passport and shows that it belongs to Richard.
Possessive pronouns are often used to contrast two things of the same type that belong to or are associated with different people. For example, Sarah’s house is much bigger than ours.
Her parents were in Malaya, and so were mine.
He smiled at her and laid his hand on hers.
Is that coffee yours or mine?
My marks were higher than his.
Fred put his profits in the bank, while Julia spent hers on a car.
That’s the difference between his ideas and ours.
It was his fault, not theirs.
used with of
1.109 Possessive pronouns are used with of to add information to a noun phrase. This structure suggests that you are talking about one of a group of things.
For example, if you say a friend of mine you are talking about one of a number of friends whereas if you say my friend you are talking about one friend in particular.
He was an old friend of mine.
A student of yours has just been to see me.
David Lodge? I’ve just read a novel of his.
It was hinted to him by some friends of hers.
The room was not a favourite of theirs.
1.110 For other ways of showing that something belongs to someone or is connected with them, see paragraphs 1.211 to 1.221.
Referring back to the subject: reflexive pronouns
1.111 When you want to show that the object or the indirect object of a verb is the same person or thing as the subject of the verb, you use a reflexive pronoun.
Some verbs are very frequently used with reflexive pronouns. For information about these, see paragraphs 3.26 to 3.31.
Here is a table of reflexive pronouns:
singular plural 1st person myself ourselves 2nd person yourself yourselves 3rd person himself
herself
itself themselves
1.112 Unlike personal pronouns and possessive pronouns, there are two forms of the reflexive pronoun used for the second person. You use yourself when you are talking to one person. You use yourselves when you are talking to more than one person, or referring to a group that includes the person you are talking to.
used as object
1.113 You use a reflexive pronoun to make it clear that the object of a verb is the same person or thing as the subject of the verb, or to emphasize this.
For example, John killed himself means that John did the killing, and he was also the person who was killed.
He forced himself to remain absolutely still.
She stretched herself out on the sofa.
I’m sure history repeats itself.
We all shook hands and introduced ourselves.
The boys formed themselves into a line.
Here is the question you have to ask yourselves.
You also use reflexive pronouns to show or emphasize that the indirect object of a verb is the same person or thing as the subject of the verb. For example, in the sentence Ann poured herself a drink, Ann did the pouring and she was also the person who the drink was for.
Here’s the money, you can go and buy yourself a watch.
1.114 Reflexive pronouns are not usually used with actions that people normally do to themselves, such as washing, dressing, or shaving. So you do not usually say He shaves himself every morning.
You can, however, sometimes use reflexive pronouns with these actions for emphasis, or to talk about a surprising event, such as a child doing something that they were not previously able to do.
used as objects of prepositions
1.115 If the subject of a clause and the object of a preposition refer to the same person, and the clause does not have a direct object, you use a reflexive pronoun after the preposition.
I was thoroughly ashamed of myself.
Barbara stared at herself in the mirror.
We think of ourselves as members of the local community.
They can’t cook for themselves.
However, if the clause does have a direct object, you usually use a personal pronoun after the preposition.
I will take it home with me.
They put the book between them on the kitchen table.
I shivered and drew the rug around me.
Mrs Bixby went out, slamming the door behind her.
Note that if the clause has a direct object and it is not obvious that the subject of the clause and the object of the preposition refer to the same person, you use a reflexive pronoun. For example, The Managing Director gave the biggest pay rise to himself.
used for emphasis or contrast
1.116 Especially in speech, people sometimes use reflexive pronouns rather than personal pronouns as the object of a preposition, in order to emphasize them.
…people like myself who are politically active.
…the following conversation between myself and a fifteen-year-old girl.
The circle spread to include himself and Ferdinand.
People like yourself still find new things to say about Shakespeare.
There is always someone worse off than yourself.
With the exception of a few Algerians and ourselves, everyone spoke Spanish.
1.117 You can use reflexive pronouns in addition to nouns or personal pronouns. You usually do this in order to make it clear or to emphasize who or what you are referring to.
I myself sometimes say things I don’t mean.
Sally herself came back.
You also use a reflexive pronoun to compare or contrast one person or thing with another.
His friend looked as miserable as he felt himself.
It is not Des Moines I miss, but Iowa itself.