One of those dastardly little conundrums of self-editing is the apostrophe.
Our writing center at the institution where I taught had a handout titled “Rogue Apostrophes,” in recognition of the way these nasty squiggles had a way of popping up here and there in student papers, wherever the mood seemed to strike them.
””””””’ !
As with many punctuation marks, misplaced apostrophes don’t always get in the way of a reader’s understanding. But they can. When readers encounter something that looks as if it was a possessive but turns out not to be, they’ll mentally backtrack to clear up the confusion. Sometimes the reader doesn’t even notice the glitch in his or her attention, but it’s there all the same.
And even the slightest glitch in attention means that the reader has been kicked out of your story, even if just for a moment. Not good.
There are only three things you need to know about apostrophes, one easy rule and two with some complications that you can learn to handle.
Rule 1 (the easy one): NEVER USE AN APOSTROPHE TO FORM A PLURAL.
Not even when it looks as if an apostrophe might be helpful, as in numerals and letters. This rule reflects the most recent style preferences, so if you learned differently, it’s time to change.
Not “I earned A’s in my math classes.”
But “I earned As in my math classes.”
Not “My scores were all 2’s.”
But “My scores were all 2s.”
Not “I learned my ABC’s”
But “I learned my ABCs.”
Trickiest: In family names
Not “My cousins, the Simpson’s, are coming to dinner.”
But “My cousins, the Simpsons, are coming to dinner.”
Just apply this rule ACROSS THE BOARD.
Rule 2: USE APOSTROPHES TO FORM POSSESSIVES.
When something belongs to something else, that’s the time for an apostrophe.
“I used Jane’s cookie recipe today.”
“The house’s paint job needed touching up.”
Two situations can give you fits:
A) PLURAL possessives—where does that darn squiggle go?
Here’s a rule of thumb that will help you: FORM THE PLURAL FIRST, THEN ADD THE APOSTROPHE.
“I like the trees’ colors in fall.”
Family names are the worst!
The plural of the family name Simpson is Simpsons.
The plural possessive (something belongs to the entire family named Simpson) is Simpsons’ (Not Simpson’s—that’s Mr. or possibly Ms. Simpson, by him- or herself).*
So: “The Simpsons’ new car is really expensive.”
“We went over to the Simpsons’ yesterday” (“house” is understood).
And:
“The families’ main concern was the change in their insurance premiums.”
Most annoying are family names that sound as if the possessive is built into the plural. For example:
The plural of “Wilkes” as a family name is “Wilkeses,” so if you want to talk about something that belongs to the entire Wilkes family, it’s “the Wilkeses’ house.”
Aggravating but true!
The position of the apostrophe is sometimes the only way you can tell whether you have a singular or plural owner:
“The girl’s dresses filled the closet” vs. “The girls’ dresses filled the closet.”
REMEMBER: FORM THE PLURAL FIRST.
B) Hidden possessives—you really need an apostrophe for that?
Yep. Think of it this way:
A wait of four days is something created by those four days, so in a logical sense, the wait belongs to the days.
So: “We had a four days’ wait.”
Remember: Form the plural first, where appropriate.
So: “It was a long day’s wait.”
Any mention of time used to modify (in front of) another noun should have this tricky apostrophe: weeks, years, months, centuries, etc.
Rule 3: APOSTROPHES INDICATE CONTRACTIONS—where a letter has been left out.
Most of these are straightforward, still so natural to us that we won’t mess them up often. I almost never see “cant” for “can’t” or “doesnt” for “doesn’t”—and I really have to discipline my word-processor if I want to deliberately make that mistake.
Two cases, though, tie us into knots:
A) Its vs. It’s
You’ve run into this one, I bet.
It’s maddening because “its” is a possessive and therefore, by Rule 2 above, should have an apostrophe. But it’s a special form of possessive, a possessive pronoun, like “her” or “their” or “his”: her dog, his cat, their pet lion, its paws.
So, as the sentences above illustrate, the ONLY TIME “it” and “s” get an apostrophe is when they form the contractions for “it is” or “it has.”
“It’s about time you got home.”
“It’s been a long time since you left.”
To be honest, this messy little exception gives so many people trouble that, if I were you and I had trouble remembering, I’d feel no shame in simply looking it up.
B) Let’s vs. Lets
This contraction may be in the process of disappearing. I admit to missing it from time to time, in writing I’m critiquing and even in my own. Still, “let’s” is a contraction for “let us,” so it’s legally entitled to an apostrophe.
These rules cover almost every situation you’re likely to find yourself in if you’re writing in Standard Written English (which is what editors, agents, publishers, and most readers expect). If you encounter something that doesn’t seem to fit, you can always search the web until you find a helpful rule.
It’s worth noting, too, that publications almost always specify a “style sheet” such as AP or Chicago Manual of Style, or provide their own. If you’re submitting to particular magazine, do what they say, regardless of “the rules.”
*One minor point I left out above so as not to add confusion: Current style specifies that possessives of PROPER NAMES take not just an apostrophe, but an apostrophe-s.
Not: “That is James’ car”
But: “That is James’s car”
Here’s a quick quiz you can try!
1) There were two Angela’s/Angelas in my high-school class.
2) We went to the Smiths’/Smith’s party last night.
3) The cat licked it’s/its fur constantly.
4) My friend made a lot of money during the late 1990’s/1990s.
5) I felt as if I’d put in a lifetimes/lifetime’s work.
Trick question:
6) Be sure to pick up the dog’s/dogs’ toys.
CONTACT ME AND I’LL EMAIL YOU THE ANSWERS IF YOU WANT!
Trust me, readers find it distracting to see an em dash in every paragraph. Some editors don’t want to see one on every page. Their point of view is that the em dash is like any other repetitive word in a manuscript. As a tool, it’s useful as a way to emphasize certain ideas, and can also be used to good effect in the place of a semicolon. In my opinion, the em dash should be used sparingly to be most effective.
Courtesy of Indies Unlimited, Melinda Clayton shares her experiences with 
Just Can't Help Writing 