1. Possessives and Apostrophes
Adapted from Real Good Grammar, Too by Mamie Webb Hixon

2. Singular Nouns and Indefinite Pronouns
Add '-s to singular nouns and indefinite pronouns: Monique's motorcycle everybody's enemy today's task the valedictorian's victory at the owner's expense Add '-s to singular nouns ending in -s: Chris's cravings Dr. Davis's desk the boss's boyfriend Dr. Evans's event or Dr. Evans' event

3. Nouns Ending in –s or -es
Add an apostrophe to plural nouns ending in -s or -es:
ladies' lingerie
eleven years' experience
two weeks' time
Add '-s to plural nouns not ending in -s:
men's medicine
children's chatter

4. Compound Words and Groups
Add '-s to the last word in compound words or groups: brother-in-law's broken laptop someone else's expectations Add '-s to the last name when indicating joint ownership: Stefan and Selina's sailboat Peyton and Parker's party Add '-s to both names if you intend to show ownership by each person: Richard's and Randall's rights Katie's and Chloe's clothes

5. Possessive Pronouns
Possessive pronouns change their forms without the addition of an apostrophe: Her house is hers. His home is his. Your youth is yours. Their theory is theirs. Our obstacles are ours. It indicates its ill intent.

6. Gerunds
Use the possessive form of a noun preceding a gerund: Their thinking thrills me. My mowing the marigolds made him mad. Do you mind our missing the meeting? A gerund is an –ing verb that is acting as a noun. To test an –ing verb to see if it is a gerund, check to see if you can replace it with a pronoun: This thrills me. That made him mad. Do you mind it? If it is a noun – or if it acting as one – it can be possessed, so Their thinking, not them thinking My mowing, not me mowing Our missing, not us missing

7. Special Apostrophes
Add '-s to words, symbols, numbers, letters, and initials to show that they are plural: Target trades in items from TV's to tomatoes. The novel normalizes nationalism in the 1990's. I’m uninterested in if's, and's, or but's. Palmer protected the POW's. Earle earned all A's and F’s.