Hear that? That’s the sound of an apostrophe. It’s like listening to a hoot owl blink. If we listened to a whole symphony of apostrophes, it would sound the same, like a bunch of hoot owls blinking. Nothing. That’s because apostrophes are not even punctuation, but part of the spelling, little symbols to help guide and inform our eyes. We talk right on by them, and we never hear them:

the summer of ’67
two weeks’ notice
mind your p’s and q’s
check their I.D.’s

Not a whisper, like they aren’t even there. We hear periods and commas, colons and semicolons, exclamation points and question marks, a pause, a stop, a restart, surprise, query, but never do we hear an apostrophe. That’s why they are so hard to use. Our ears cannot help us. Bow hunters stalking wild turkeys would be wise to study apostrophes.

In the 1980s, a grammarian named Robert Pinckert wrote Pinckert’s Practical Grammar, in which he observed that we misuse apostrophes not because we are stupid, but because apostrophes are about as useful as gums on a barracuda. “Strong players in the Game of English,” says Pinckert, “love to find misused apostrophes and then laugh or scowl . . . at the weaker players. You must learn about apostrophes, not because they’re worth knowing, but to protect yourself.”

Pinckert's a little harsh, but he has a point: Once we get beyond forming contractions—which is simple, and you already know how to do that—and forming possessives—which we've already discussed (See Tips: “Farmers Market Syndrome” and “Possessed”)—the other apostrophe rules seem whimsical: Let's stick one in here, but not over there. Okay.

PROTECTING YOURSELF FROM THE GRAMMAR BULLIES

First, we don’t need an apostrophe when we simply want to make a singular word plural. Otherwise, we end up writing signs for banana’s and apple’s. It’s just a plural, nothing fancy; add an s: bananas, apples. No apostrophe. Most of the bullies will now leave you alone.

FILLING IN MISSING NUMBERS AND LETTERS

Second, after we get past the contractions and possessives, we use apostrophes mostly to replace missing numbers in a date and missing letters in a word. The latter need usually arises when we try to write dialogue:

I was in California in '67, the Summer of Love, but got lost in San Bernardino.

I's jus' fixin' to whi' u' sun' grits. Wan'sun?

ABBREVIATIONS WITHOUT PERIODS

Then we get into an area that changes with the times, the whimsical part, and right now The Modern Language Association, The Chicago Manual of Style, and publishers' style guides all recommend not using an apostrophe in plurals of numbers written as nouns, or in abbreviations—but only abbreviations without periods (abbreviations with periods are different, and I'm sure that whoever thought that one up had a very good reason, but I don't know what it is; more below):

figure 8s, the 1990s, IRAs, the ABCs, YMCAs, IOUs

ABBREVIATIONS WITH PERIODS

Now more whimsy, disguised as rule: If an abbreviation has more than one period, form the plural by adding an apostrophe and an s: M.D.’s, Ph.D.’s, I.D.’s. If there is only one period at the end, add the s before the period and skip the apostrophe: vols., yrs. But don’t follow this one blindly, or the plural of Mr. becomes Mrs.; use Messrs. and Mmes. It's so continental.

MAKING SINGLE LETTERS AND CERTAIN WORDS PLURAL

This is the most confusing. According to the Chicago Manual of Style, when we need to distinguish letters or words, we italicize them: the letter q; a capital W; the suffix es; the word but. But not one grammar book I can find is clear on whether the plural of those letters and words requires an apostrophe. This is the clearest rule I can offer you: We have two choices: either we italicize them and add a Roman s with no apostrophe; or we surround the letters or words in quotation marks and add the apostrophe.

How many ns are in the title Finnegans Wake?

Write with fewer "but’s."

One more of his "hallelujah's" and Samantha vowed she would nail him with a blowdart.

The only time we add an apostrophe to an italicized word is when we might otherwise confuse our reader, as we see in this sentence:

Dot the is and cross the ts. Dot the i's and cross the t's.

WARNING:

Always use an apostrophe after an indefinite pronoun to form the possessive: anybody’s guess, everybody's nightmare. But never use an apostrophe with the already possessive pronouns: its, hers, his, ours, yours, theirs, whose, and oneself. The most infamous of all apostrophes is the one that separates it from s to form the contraction for it is or it has. The possessive its never contains an apostrophe.