Lesson: Forming plurals and the role of the apostrophe
A common mistake in English writing appears, strangely enough, when we write lists of dos and don’ts. Many people mistakenly write “do’s and don’ts” (with an apostrophe in “dos”).
The proper way is to write dos and don’ts—with no apostrophe in dos.
Apostrophes are reserved for showing possession. Take this sentence, for example: This is Sally’s cookie. Here, the apostrophe in “Sally’s” shows us that the cookie is reserved for Sally. Sally possesses the cookie.
We also use apostrophes to indicate missing letters in contractions. When we write “shouldn’t,” for example, the apostrophe indicates the missing letter “o.”
Apostrophes rarely form plurals. This is why if you have more than one “do” on your list, you have “dos,” not “do’s.” (The only time I know of when apostrophes form plurals is with lowercase letters. Example: There are five x’s.)
Another common apostrophe conundrum
Along with “dos,” another common apostrophe mistake comes when people write about years. When writing, for instance, about the ten-year period that made up the 1990s, you would not use an apostrophe before the letter “s.” The proper way to refer to a date range, whether it is the 1990s or the 1800s or any other period of time, is to do like you do with your multiple “dos.” Simply add an “s,” and forget about the apostrophe altogether.
Erin Servais is the founder of Dot and Dash, LLC, an author-services company focusing on women writers and offering a range of editing, coaching, and social media packages.
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Grammar Party 
Zounds. I was always told that apostrophes are needed to indicate plurality if their absence hurts comprehension.
EX: “Always dot your i’s”, NOT “Always dot your is”
Similarly, with your example, to make sure no one thought I was talking about Microsoft DOS, I’d say “Do’s and don’ts”
Thoughts?
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You’re right about the lowercase letters. I went through The Chicago Manual of Style again and saw that section 7.14 gives the example of lowercase letters becoming plural by using the apostrophe. (But not capital letters.) I guess not even copy editors are perfect. Darn. I updated this post to include the lowercase letter exception.
As for your Microsoft DOS example, I would just avoid this problem by only using Apple products. All joking aside, the lowercase letter exception was the only I found in that style guide–though, I can’t vouch for all style guides. Chicago does specifically point out that “dos and don’ts” is spelled as I explained in this post.
Thanks for your comment. It’s much appreciated.
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I know ages ago when I was teaching composition courses and working in a writing center to pay for my costly tuition, I had 3 different style guides I had to switch between when helping people in different majors figure out how *THIS* class or that one would require them to spell and cite. It was absolute H-E-double-hockey-sticks for all of us. I was also in that situation, of course, as a student enrolled in a wide array of classes. The only saving grace is that the entire English department told anyone who’d decided their major to use the guidelines for that. After all, the point should ultimately be sufficient skill for the field you choose, not forcing science majors to flip between what various humanities course instructors used for THEIR work then going back and trying to still do their own assignments well.
Anyway, I remember AP Style Guide uses do’s and dont’s and I think MacMillan also does (I remember fumbling around through an instructor guide, a 700-page guide, mind you, and seeing the wild array of how people do it. The one I HATE is do’s and don’t’s… that is heinous. Thankfully, that isn’t really for academia).
Style guides truly were proof not so much of the fluid nature of English… but the perverse nature of scholars who all feel too elitist and entitled to settle for one way of doing something that ultimately should only have the goal of clear communication. In that respect, do’s and don’ts does indeed read more clearly. My own feelings are rather mixed, but I read do’s more immediately without hiccup than I read dos (largely because when do, a verb that is otherwise pretty much always a verb that adds -es to change from plural to singular subject agreement, becomes dos/do’s, our brains already have to leap to the vast land of exceptions to the [already loosey-goosey] “rule”).
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What about italicizing “do” and “don’t” before the s to identify those words as noun terms instead of their usual verb use? dos and don’ts
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That certainly is one way to handle it. For some reason, I don’t like when only part of a word is italicized. To me, it looks confusing. But that is totally my personal preference. Many people may find your idea very helpful.
Thanks for your comment.
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I think part of the confusion on years comes from the use of apostrophes to leave out the century when talking about a decade; for example ’80s, ’90s. You’re entirely correct about not needing an apostrophe before the s (unless it’s something belonging to a year – “1994’s top-selling single” – normal possessive rules apply).
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Many authorities also allow the use of the apostrophe in the plural of capital letters if the absence of the mark would be confusing, like the Oakland A’s.
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I amd using dos and don’ts in the title of a book I am writing and although I know in my heart you are correct, it just looks wrong to me. Even worse I am talking about computers so dos could easily be read as dos. What to do, maybe I will go with the italicised idea. Thanks for this dilemma 🙂
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As a scientist, I’m used to seeing italics for foreign words (e.g., species names) and phrases (e.g., “in vitro”, “sensu stricto”). An italicized “do” followed by a plain “s” would make me wonder if I was completely misreading it.
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Ok. But, doesn’t it depend on what the unabbreviated sentence was? The most common unabbreviated phrase I hear is “Do this and do not do that.” So, couldn’t you abbreviate Do this, as Do’s?
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Leaving out the apostrophe only hurts comprehension to people who don’t understand grammar.
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The history behind using apostrophes for plurals AND contractions is that originally, all apostrophes implied a contraction. The term apostrophed still means shortened, abbreviated or contracted in modern English. In old English, it was normal to add the ending -es for possessive adjectives. So what we now write as John’s book, or Elizabeth’s horse, would once have been written Johnes book or Elizabethes horse. Over time we have dropped the letter e altogether, adopting the contracted version as standard. The apostrophe in possessive adjectives is a replacement for the letter e.
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The AP Stylebook recommends ‘Do’s and Don’ts’.
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Like the comment about the Oakland A’s, what about grades…He had 7 A’s last semester or 7 As?
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Liz, I prefer As. However, if I’m concerned there will be confusion with the word “as,” which context and word placement should prevent, I would consider using an apostrophe.
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