What are the four rules for possesives?

Answer 1

There are three rules.

1 All singular nouns form the possessive by adding 's: man's, house's, fox's, boss's

2 All plural nouns ending is s form the possessive by adding the apostrophe alone: houses', foxes', bosses'

3 Plural nouns not ending in s form the possessive like singulars, by adding 's: men's, bacteria's

A common error is to use the plural-in-s form, an apostrophe alone, for singulars ending in s. Do not do it. Possessive singulars like boss's and princess's are pronounced just like simple plurals: bosses, princesses. If you think Socrates's wife "sounds wrong" you may use "wife of Socrates" instead. But do not use Socrates' wife.

Answer 2

The four rules for possessives are using an apostrophe followed by -s to show possession for singular nouns (e.g., the dog's bone), using only an apostrophe for plural nouns ending in -s (e.g., the dogs' bones), using -s' for plural nouns that do not end in -s (e.g., the children's toys), and using an apostrophe after the second word for joint possession (e.g., Mary and John's house).