2.185 Indicating close connection: apostrophe s / 's

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.
• They also prepare the university's budget.
• ...the paper's political editor, Mr Fred Emery.
• There was a raid on the Democratic Party's headquarters.
• What is your government's policy?

2.186

Apostrophe s ('s) is sometimes added to a noun referring to an object when specifying a part of it or a quality or feature that it has.

• I like the car's design.
• You can predict a computer's behaviour because it follows rules.

Apostrophe s ('s) is used after nouns and names referring to places to specify something in that place.

• He is the administrative head of the country's biggest city.
• The city's population is in decline.
• ...Britain's most famous company.

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If you want to emphasize that something belongs or relates to a particular person and nobody else, you use 'own'. 'Own' can be used after the possessive form of a name or noun, as well as after a possessive determiner.

• Professor Wilson's own answer may be unacceptable.
• We must depend on David's own assessment.

If you are specifying a number, you put the number after 'own'.

• ...the Doctor's own two rooms.