081 : -’s (your sister’s name) and of … (the name of the book)

   A   

We use -'s (apostrophe + s) mostly for people or animals:

• Tom's computer isn't working. (not the computer of Tom)
• How old are Chris's children? (not the children of Chris)
• What's (= What is) your sister's name?
• What's Tom's sister's name?
• Be careful. Don't step on the cat's tail.

You can use -'s without a noun after it:

• This isn't my book. It's my sister's. (= my sister's book)

We use -'s with a noun (Tom/friend/teacher etc.). We do not use -'s with a long group of words.
So we say: 

     your friend's name  but
     the name of the woman sitting by the door

 

Note that we say: 

     a woman's hat (= a hat for a woman) 

     a boy's name (= a name for a boy)

     a bird's egg (= an egg laid by a bird) etc.

 

 

   B   

With a singular noun we use -'s:

     my sister's room (= her room - one sister)
     Mr Carter's house (= his house)

 

With a plural noun (sisters, friends etc.) we put an apostrophe (') at the end of the word:

     my sisters' room (= their room - two or more sisters)
     the Carters' house(= their house - Mr and Mrs Carter)

 

If a plural noun does not end in -s (for example men/women/children/people) we use -'s:

     the men's changing room
     a children's book(= a book for children)

 

You can use -'s after more than one noun:

     Jack and Karen's wedding
     Mr and Mrs Carter's house

 

 

   C   

For things, ideas etc., we normally use of ( ... of the water / ... of the book etc.):

     the temperature of the water (not the water's temperature)
     the name of the book
     the owner of the restaurant

 

Sometimes the structure noun + noun is possible (see Unit 80):

     the water temperature 

     the restaurant owner

 

We say the beginning/end/middle of ... / the top/bottom of ... / the front/back/side of ... :

     the beginning of the month (not the month's beginning)
     the top of the hill
     the back of the car

 

 

   D   

You can usually use -'s or of ... for an organisation (= a group of people). So you can say:

     the government's decision   or   the decision of the government
     the company's success   or   the success of the company

 

It is also possible to use -'s for places. So you can say:

     the city's streets
     the world's population
     Italy's prime minister

 

 

   E   

You can also use -'s with time words (yesterday / next week etc.):

• Do you still have yesterday's newspaper?
• Next week's meeting has been cancelled.

 

In the same way, you can say today's / tomorrow's / this evening's / Monday's etc.

 

We also use -'s (or -s' with plural words) with periods of time:

• I've got a week's holiday starting on Monday.
• Julia has got three weeks' holiday.
• I live near the station - it's only about ten minutes' walk.

 

 

 

※ changing room :