This will be a short and sweet post because, well, there are very few rules for apostrophe usage. CAVEAT: Certain publishers will have in-house rules. These are the basics to follow, but don’t use them to argue with your editor. Please!
1. DO NOT USE AN APOSTROPHE TO MAKE SOMETHING PLURAL. I have two car’s is sooo wrong.
2. DO use an apostrophe with all contractions: they’re, that’s, we’ve, he’s, she’d, etc. all use apostrophes. Heck, even ain’t has one.
3. It’s means IT IS. It does not indicate possession. This is one exception to the possession rule (along with his and hers. Yes, hers does not have an apostrophe)
4. If it ends in a letter other than “s,” add ‘s to show something belongs to it. Example: Sally has a book. That is Sally‘s book.
5. If it is a plural noun that is not proper (i.e. not capitalized) and ends in an “s,” add an apostrophe to the end (yes, I know the grammar rules have gone back and forth between adding an apostrophe and add ‘s, but this is how they’re teaching it these days, per the Copyeditor’s Handbook). Example: The octopus’ lair.
HERE is where the real dissent lies.
6. Proper noun posession: We have many names that end in “s,” like Jesus and Moses and Socrates. The Chicago manual of style recommends using an ‘s for all proper names that end in “s” but do not have a “z” sound. Jesus’ and Moses’ are standarized forms of showing possession for those two names. Example: “That it Thomas’s book you’re holding” versus “That is Socrates’ book you have.”
NOTE: When in doubt and the word ends in “s,” simply add an apostrophe: “That is Thomas’ book you’re holding.” Since this rule is most subject to house style guidelines, you may end up making corrections under either guideline.
7. Plural possessives: add an apostrophe only. Example: That is the my parents’ car.
It’s (it is) funny that its (possessive) leaf is purple instead of green.
Bob Jones has a red car. That is Bob’s car.
Alexis Jones has a blue car. That is Alexis’s (or Alexis’) car.
The two cars both share a garage. That’s the cars’ garage. (not that inanimate objects can truly own anything)
Mr. Jones owns a red car. It is Mr. Jones’ red car.
The Mr. and Mrs. Jones own a blue car. That is the Joneses’ blue car.
Check back next Monday for more SMUGness, and if you’ve missed previous lessons, find them below. As usual, please post your SMUG questions for me to answer!