Практическая грамматика

The Genitive (Possessive) Case
The possessive case represents in Modern English the Old English genitive case but it is much narrower in its meaning and function, it expresses possession with various shades of meaning depending on the lexical meaning of the words. In Modern English the use of the possessive case is restricted chiefly to nouns denoting living beings and its syntactical function is exclusively that of an attribute:
The Blind Girl, greatly agitated, rose, and led the Carrier’s little wife
aside. (Dickens) Annette’s clear eyes opened…(Galsworthy)
With nouns denoting inanimate things and abstract notions the possessive case relation is rendered in English by of-phrase (which then is an equivalent of the possessive case):
…the first light of the winter dawn crept round the edges of the blinds. (Shaw) The door of his room was open… (Galsworthy)
The of-phrase may also be used with nouns denoting living beings:
The father of Keesh had been a very brave man…(London)
1. The possessive case is formed by adding -'s (the apostrophe s) to the noun in the singular and only ' (the apostrophe)-to plural forms ending in -s.
singular: a girl's book
plural: a girls' school
Note 1. Nouns forming the plural by changing the root vowel take the apostrophe both in the singular and in the plural:
singular: a man's hat
plural: men's hats
Note 2. Nouns ending in -s form the genitive case in two ways:
Dickens' novels,
Dickens's novels.


Note 3. Sometimes the apostrophe s may refer to a whole group of words (the group-genitive):
This is Jane and Mary's room.
The last word of the group need not even be a noun:
I shall be back in an hour or two's time.
As to its use the genitive case falls under:

1. 
   The Dependent Genitive (Possessive)
   
2.