What are the rules for forming possessive nouns with names ending in 's'?

When it comes to forming possessive nouns with names ending in 's', there are a few rules to keep in mind.

1. For singular nouns ending in 's':
- If the singular noun ends in 's', you can form the possessive by simply adding an apostrophe ('s) after the 's'. For example: James's car, Charles's book.

2. For singular nouns ending in a sound other than 's':
- If the singular noun ends in a sound other than 's', you should add an apostrophe ('s) after the noun. For example: Max's house, Chris's bike.

3. For plural nouns ending in 's':
- If the plural noun already ends in 's', you only need to add an apostrophe (') after the 's'. For example: the girls' toys, the dogs' leashes.

4. For plural nouns not ending in 's':
- If the plural noun does not end in 's', you should add an apostrophe ('s) after the noun. For example: the children's books, the men's shoes.

5. For joint possession:
- When two or more people possess something together, you only need to add an apostrophe (') after the last noun. For example: John and Sarah's car, the company's employees' benefits.

It is important to note that these rules apply to most names ending in 's', but there are exceptions and variations depending on the specific name or style guide being followed.