Even though most people would say NEVER use an apostrophe s to make something plural, there are a select handful of situations where it’s correct. These are those situations.
It almost feels irresponsible to write this list. In general, the rule about using an apostrophe s to pluralize something is… NEVER USE AN APOSTROPHE S TO PLURALIZE SOMETHING. Apostrophe s pluralization has replaced your/you’re as the most glaring English mistake on the Internet. It sure would be easier to just say “never do it.”
But that’s the equivalent of abstinence-only sex education. Saying “never pluralize with apostrophe s” is just a recipe for leaving curious people unprepared with it comes time to maybe or maybe not use an apostrophe s for pluralization. And this website is not a ninth grade health class in Murfreesboro, Tennessee. So I’m daring to discuss the 11 situations (quite possible the ONLY 11 situations) where you just might be able to get away with using an apostrophe s to make something plural.
One disclaimer before we start. Not every style guide (AP, Chicago, New York Times, Oxford, etc.) agrees on all of these. But some or most are on board, which, at least, will give you some pedantic credibility when you get into a regrettable e-argument after following one of these rules.
Here are 11 cases where it’s correct to use an apostrophe s to make a word plural. Use these the way you would use condoms and dental dams.
1 | Single lowercase letters
The key to the apostrophe s for pluralization is that it belongs in cases where the absence of an apostrophe would cause confusion. That happens with single letters, particularly ones that would form actual words with an s at the end. Example: As reads as as, while a’s reads like you were intending. So it’s widely accepted to use an apostrophe s to pluralize single lowercase letters. The phrase “mind your p’s and q’s works with apostrophe s’s” works when you’re minding your p’s and q’s with apostrophe s’s.
2 | Certain single capital letters
While “mind your p’s and q’s” is ok, if you went with capitals, you’d write “mind your Ps and Qs.” The capitalization takes out the confusion. But… in some cases, single capital letters still need an apostrophe s to go plural. A’s is better then As, because “As” is a word. S’s is better than Ss, because you’re not on a ship or talking about the Third Reich.
3 | Acronyms, initialisms and abbreviations using periods
You’d write Ph.D.’s, but not PhDs. This one is more for aesthetics than anything, because God forbid your words aren’t beautiful. Why, you’d give Mitch Albom a case of the vapors! So Ph.D.s looks awkward and ugly; Ph.D.’s looks more elegant and structured. PhDs also looks good, I guess, in its punctuation-free minimalism. Sometimes it feels like the English authorities just make things up as they go.
4 | Acronyms, initialisms and abbreviations without periods that end in S
It’s legal to write “I attended one of the 75,000 BHS’s in Ohio,” since BHSs wouldn’t look or read properly. And at my BHS, we learned to read properly. At least I think we did. We spent a lot of time in English class watching movies.
5 | The Oakland A’s
A’s is short for Athletics. Athletics doesn’t need the apostrophe s for pluralization (although, based on Facebook posts, the majority of people DO think team names get an apostrophe thrown in). A’s keeps the apostrophe because it’s a single letter, yes; it would form the word As without the apostrophe, yes; but, most of all, because they trademarked that name and made a century’s worth of merchandise around it. Big Merch cares not for your semantic trifling.
6 | Pluralizing words referring to themselves
Sometimes words aren’t being used for their meaning but for themselves. That’s a complicated way of describing a sentence like, “No if’s, and’s or but’s” or “He gives us so many maybe’s that he never commits to anything.” You could also italicize that as, “He uses so many maybes that he never commits to anything.” But you can’t do that if you’re in a situation where italics aren’t an option like handwriting or Comic Sans.
7 | Symbols
When you’re talking @’s or &’s or ?’s — or the extra trippy “‘s and ”s — an apostrophe s is acceptable for pluralization. I’m not sure if this applies to pluralizing semi-popular modern rapper Ty$; it may or may not be correct to say, “There are plenty of semi-popular rappers, like your Tygas and your Ty$’s.” There might be someone out there who’s qualified to reconcile complex grammar and punctuation anomalies and hip-hop, but I’m not that guy. Yet. Call me, XXL Style Manual editors.
8 | Numbers… maybe
The other 10 situations on this list fall under the umbrella of “mostly correct.” Using apostrophe s to pluralize numbers is the only one that falls under “mostly incorrect.” Most places say you shouldn’t write “He was shooting all 6’s and 8’s at the craps table.” They say you should go with “sixes and eights” or, in lieu of that, “6s and 8s.” But a scant few style guides still accept pluralizing numbers with apostrophes. Regardless, none of them accepts pluralizing years with apostrophe s; there’s no 1990’s or ’90’s, just 1990s and ’90s. I went with ’90s so that when someone from Buzzfeed inevitably comes here the lesson will resonate better.
9 | The Go Go’s
It’s only right because they made it their official band name. I don’t want to be the one who also breaks it to them that We Got the Beat isn’t grammatically correct either. I think I just blew my shot with Belinda Carlisle.
10 | Children’s hospital, depending on how you view the role of children
The question: In a children’s hospital, is “children” a noun or an adjective? If it’s a noun, “children’s hospital” means the hospital is possessed by children. (Not demonically, the kids aren’t sick from Satanic takeovers.) If it’s an adjective, “children’s hospital” is using the apostrophe s to pluralize a word that, itself, is irregularly plural. Either way, there’s no such word as “childrens” without an apostrophe, so you may or may not be using the apostrophe to pluralize it in your own mind. I like this one because it’s totally NOT confusing.
11 | Do’s and don’ts
This one causes some debate. There are three possibilities: Dos and don’ts, do’s and don’ts, and the incredibly convoluted do’s and don’t’s. Sources generally agree on using the apostrophe s to pluralize do’s, lest it be confused with the Spanish word for two or the old IBM operating system. But as for the rest of the phrase… that’s tough. Don’t’s would be consistent with do’s, but looks absurd. Don’ts also looks unusual, with the s awkwardly tacked on post-contraction. So the answer is… do what you feel. Or don’t.