We normally use 's and s' only for people and some living creatures:

- Collective nouns: My family's country house

- Higher animals: The lion's mane.

- Indefinite pronouns: Someone's responsibility.

- Personal names: Tom's pen.

- Personal nouns: The boy's new shoes.

The 's genetive is also used with certain kinds of non-living nouns:

- Churches and cathedrals: St Francisco's Church.

- Fixed expressions: Journey's end.

- Geographical reference: Argentina's economy.

- Institutional reference: European Economic Community's currency.

- Money's worth: Ten pesos' worth of petrol.

- References to cars, planes and ships: The plane's engines.

- Time references: Two days' trip.

The use of the "of-construction" to connect two nouns:

- Abstract reference: The cost of living.

- Parts of things: The top of the page.

- Things: The book of the film.

Meanings of the Genetive:

- Possession (answering Whose?): Mary's car.

- Regular use: Alice's chair.

- Relationship: Ann's son

- 's + favourite: This is Tom's favourite dish.

- Actions: Scott's trip.

- Purpose: Boys' school.

- Characeristics: Alison's limp.

Joint possession is indicated by the apostrophe on the second or last element. Eg.

 Peter and Mary's children.

When a number of individuals possessors of separate items are mentioned each takes its own's. Eg.

Tom's and Paul's sons.

The Genetive with ellipsis:

The 's/s' construction can be used on its own when we refer to:

- A noun that is implied: My car is faster than John's.

- Churches and colleges named after saints: St Bosco's.

- Medical practitioners: At the dentist's.

- Shops and business: The chemist's.

- Well-known restaurants with names of their owner: Luigui's.

- Where someone lives: I'll meet you at Mary's.

The Double Genetive:

It is a combination of the 's and the of construction. Eg.

This is an opera of Verdi's.