Use: We use
possessive pronouns/adjectives and the possessive form
of a noun to show that something belongs to someone or
's is added to the end of singular nouns and irregular plural nouns:
castle ► castle's moat
boss ► boss's desk
men ► men's locker room
' is added to regular plural nouns:
cars ► cars' windshields
bees ► bees' wings
Note: Only add an s to the pronoun it.
Its contents are under the scrutiny of authorities.
It's not what you think. = It is not what you think.
I have a large house. >> My large house costs too much to heat in the winter.
You are guilty. >> Your guilt is obvious.