Possessive

Possession of people or animals

Singular 's This is my friend's book.
Plural ending on -s ' These are my sisters' books.
Plural not ending on -s 's These are the children's books.
Names ending on -s -x -z ' / 's This is Jess' / Jess's book.

 

Possession of things

Singular ... of ... He was on the cover of a magazine.
Plural ... of ... The noise of the machines is very loud.
Location ... of ... We are in the city of London.