What is the difference between plural possessive nouns and singular possessive nouns?

Answer 1

One boy - possessive = boy's. The boy's lunch is lost.

Two, three or more boys - possessive = boys'. The boys' lunches have been stolen.

For singular possessives the form is apostrophe s = ' s

For plural possessive the apostrophe comes after the s = s '

Answer 2

Plural possessive nouns show ownership or relationship of more than one person or thing (e.g., children's toys). Singular possessive nouns show ownership or relationship of one person or thing (e.g., the dog's leash).