Certain rules must be followed while forming possessive nouns.
1. The possessive of a singular noun is formed by adding an apostrophe (') and an -s.
Examples:
2. The possessive of a plural noun is formed by adding an apostrophe (') after the -s.
Examples:
3. The possessive of a plural noun that does not end in -s is formed by adding an apostrophe (') and an -s.
Examples:
4. The possessive of a proper noun that ends in -s or -z is formed by adding an apostrophe (') and an -s.
Examples:
5. The possessive of a proper noun that ends in -s and has an ending /ez/ sound is formed by adding an apostrophe (') after the -s.
Examples:
6. The possessive of a compound noun is formed by adding an apostrophe (') and an -s to the last word.
Examples: