There are two forms in English which denote possession. Let’s take a look at them: 

  • My sister’s dog is cute.
  • The title of the book is interesting.

Both sentences use the possessive form. In the first sentence, ’s is added to the end of the noun.

For this form, if the noun ends in a s or z, then  is added to the end of the noun. 

  • My sister’s dog
  • Sanchez’ dog
  • The girls’ are ready.  *Plural

The second sentence uses the possessive form with the particle of. Compared to the ’s form, this form flips the word order and adds the particle of. Let’s look at some examples:

  • The book’s title
  • The title of the book

In both forms, the book is the possessor of the title. When the second form is used, the object being possessed moves to the front of the phrase.

When is each form used?

The main thing to consider is whether the possessor is living or nonliving. It is important to note that “living” refers to all life, not just human life.

The possessive ’s is used for living objects.

  • The dog’s home
  • The bird’s song

The of form is used for nonliving objects.

  • The legs of the chair
  • The taste of the coffee