1.205 When you refer to a specific part of someone’s body, you normally use a possessive determiner.
She has something on her feet and a bag in her hand.
Nancy suddenly took my arm.
The children wore nothing on their feet.
She thanked him shyly and patted his arm.
I opened the cupboard and they fell on my head.
He shook his head.
However, when you are describing an action that someone does to a part of someone else’s body, you often use the definite article (the), especially when the body part is the object of a preposition and when the object of the verb is a pronoun. For example, if you say She hit me on the head, head is the object of the preposition on and me is the object of the verb hit.
I patted him on the head.
He took her by the arm and began drawing her away.
You use the definite article because the owner of the body part has already been identified, and you do not need to repeat this information.
Similarly, if the object of the verb is a reflexive pronoun such as myself, yourself, and so on, you use the definite article. This is because the reflexive pronoun already refers to you or to the person who is doing the action, so you do not need to repeat this information by using a possessive determiner.
I accidentally hit myself on the head with the brush handle.
We can pat ourselves on the back for bringing up our children.
Uses of reflexive pronouns are explained in paragraphs 1.111 to 1.118.
1.206 If you want to describe something that you do to yourself or that someone else does to themselves, you normally use a possessive determiner.
She was brushing her hair.
‘I’m going to brush my teeth,’ he said.
She gritted her teeth and carried on.
He walked into the kitchen and shook his head.
1.207 You usually use possessive determiners when you refer to people or animals. You do not usually use them to refer to things that are not alive. It is, for example, more usual to say the door or the door of the room than its door.
generic use
1.208 Possessive determiners are sometimes used to talk about things that belong to or are associated with people in general, in a similar way to generic pronouns. For more information on generic pronouns, see paragraphs 1.119 to 1.123.
Your can be used when you are talking about something that belongs to or is associated with people in general, or with a person in a situation that you are imagining.
Can eating a low-fat diet weaken your hair?
Going to the gym is good for your general health.
Part of the process involves discussing your decision with a career counsellor.
In more formal English, one’s is sometimes used instead of your.
A satisfying job can bring structure and meaning to one’s life.
Our can be used to talk about all of mankind or society.
Being a child is not easy in our society.
Their can be used to refer to a person when you do not know, or do not want to specify, whether that person is male or female.
The most important asset a person has is their ability to work.
Each winner received a plaque with their award title.
other possessives
1.209 There are other ways of showing that something is owned by or connected with someone or something else. For example, you can use ’s (apostrophe s) or a prepositional phrase beginning with of.
Mary’s daughter is called Elizabeth.
Very often the person appointed has no knowledge of that company’s end product.
…the house of a rich banker in Paris.
In the opinion of the team, what would they consider to be absolutely necessary?
possessive determiners used in titles
1.210 Possessive determiners are also sometimes used in titles such as Your Majesty and His Excellency. This use is explained in paragraph 1.56.
The possessive form: apostrophe s (’s)
1.211 You usually show that something belongs to or is associated with a specific, named person by adding ’s to the name of the person, and by placing this possessive form in front of the thing that belongs to them, or is associated with them. For example, if John owns a motorbike, you can refer to it as ‘John’s motorbike’.
Sylvia put her hand on John’s arm.
…the main features of Mr Brown’s economic policy.
When you use a noun rather than a name to refer to the person, the noun phrase containing the possessive form also contains a determiner in the usual way.
…his grandmother’s house.
Your mother’s best handbag.
Note that the determiner applies to the possessive form and not to the noun that is being modified by the possessive.
spelling and pronunciation
1.212 The spelling and pronunciation patterns used to form possessives change according to the spelling and pronunciation of the name or noun. These are explained in the Reference Section.
other uses of ’s
1.213 Note that in addition to being the possessive form, the pattern ’s can also be added to words as a contraction of is or has. This is explained in the Reference Section.
showing close connection
1.214 Apostrophe s (’s) is most often added to a noun referring to a person or an animal.
I wore a pair of my sister’s boots.
Philip watched his friend’s reaction.
Billy patted the dog’s head.
It can also be used to show that something belongs to or is associated with a group of people or an institution.
She runs the foreign exchange desk for the bank’s corporate clients.