Here’s a quick and easy guide to the concept of plural possessive:
INCORRECT: Boss’ office.
CORRECT : Boss’s office. (It looks weird, but this is how it should be for singular nouns, even if they already end in “s”.)
INCORRECT: mother’s-in-law cooking
CORRECT : mother-in-law’s cooking (This is how we make a compound noun possessive.)
INCORRECT: The Davis’s cars.
CORRECT : The Davises’ cars. (You have to first make the Davis plural = Davises. Then you have to add the apostrophe to make it possessive. For PLURAL nouns that end in “s”, simply add an apostrophe after the word.)
We use “the” with the person’s name to refer to a family as a whole (father, mother, and children).
• The Jones
• The Kimes
• The Cartlidges
• We’re the Flintstones