What are the four rules for possesives?

There aren't exactly four "rules" for possessives, but here are the four main concepts to keep in mind when forming possessives in English:

1. Singular Nouns: Add an apostrophe and an "s" to the end of singular nouns.

* Example: The cat's tail is fluffy.

2. Plural Nouns Ending in "s": Add only an apostrophe after the "s".

* Example: The cats' toys are scattered across the floor.

3. Plural Nouns Not Ending in "s": Add an apostrophe and an "s" to the end of the noun.

* Example: The children's laughter filled the air.

4. Possessive Pronouns: Some pronouns show possession without using an apostrophe (e.g., mine, yours, his, hers, its, ours, theirs).

* Example: This book is mine.

Let me know if you want more detail on any of these concepts!