How do nouns form their possessive form?

Answer:

The simple basic rule is :

in the singular - add 's (apostrophe s) eg the boy's ball or the ball of the boy

in the plural - add ' (apostrophe only) eg the boys' ball or the ball of the boys.

There are exceptions to the rule.

The most common error is to add 's to the word it as in "it's cover". This is wrong. The correct form is "its cover". Only use it's to mean it is.

First answer by Plucas. Last edit by Plucas. Contributor trust: 1280 [recommend contributor recommended]. Question popularity: 3 [recommend question].