The Enigmatic Em Dash

Knowing how to punctuate properly is essential to good legal writing. Besides the semicolon, though, lawyers probably misunderstand—and as a result misuse—the em dash more than any other punctuation mark. That’s because it’s possible for a lawyer to write for an entire career without ever having to use it.

But lawyers who consciously avoid using the em dash forsake an important legal-writing tool. They’re like carpenters who choose to work with rudimentary tools instead of precision instruments. The job gets done; but the result is hardly refined.

What’s an em dash?

The em dash (—) is about as wide as a capital H. In Typography for Lawyers, Matthew Butterick dispels the myth that the em refers to the letter M. According to Butterick, the em instead refers to units of typographical measurement: “In a traditional metal font, the em was the vertical distance from the top of a piece of type to the bottom.”

The origin of the em dash is unclear. Noreen Malone, in The Case—Please Hear Me Out—Against the Em Dash recounts speculation that the em dash has existed since the Gutenberg printing press (ca. 1450s) but she also notes that it didn’t routinely appear in print until the 1700s. If true, the em dash is a recent invention compared to other punctuation marks such as the period and comma.

Em dash as utility infielder

The em dash is a versatile punctuation mark, somewhat like baseball’s utility infielder. Besides doing their own work in a sentence, em dashes can substitute for commas, parentheses, and even colons to mark a variety of interruptions.

In Writing with Style, John Trimble lists five different circumstances where em dashes can mark interruptions. I’ve listed them below, along with usage examples:

  1. Marking an interruption or break in thought: Writers overuse em dashes—well, to be fair, careless writers overuse them.
  2. Serving as a conversational colon or light bridge: One writer is known for using em dashes haphazardly—Emily Dickinson.
  3. Isolating a concluding phrase for emphasis or comic effect: Punctuating properly is necessary to write well—unless, of course, that’s not your goal.
  4. Marking a gathering-up of ideas or series of subjects: Avoiding buried verbs, minimizing prepositions, using the active voice—these are easy ways to improve writing.
  5. Inserting a parenthetical explanation, qualification, or amplification: The leading authorities on American legal writing—Wydick, Garner, and Kimble—agree that em dashes are an excellent way to set off parenthetical or explanatory material.

Skilled legal writers usually limit their em dashes to Trimble’s fifth circumstance because the other four, which all require a single dash and force the reader to stop abruptly, occur less often in legal writing.

But consider number five above. Notice how commas or parentheses wouldn’t have the same attention-grabbing effect on the explanatory phrase:

  • The leading authorities on American legal writing, Wydick, Garner, and Kimble, agree that em dashes are an excellent way to set off parenthetical or explanatory material.
  • The leading authorities on American legal writing (Wydick, Garner, and Kimble) agree that em dashes are an excellent way to set off parenthetical or explanatory material.

Sentences such as this one call for a pair of em dashes. Commas or parentheses—while grammatically acceptable—simply don’t do the job.

Misusing em dashes

Like other writing tools, lawyers can misuse the em dash. Here are some things to avoid.

  • Don’t use more than two em dashes in a sentence. Otherwise, as Trimble points out, “[y]ou’ll simply confuse your reader, and your prose will look like chopped carrots.”
  • Don’t litter your writing with em dashes. In The Practical Stylist, Sheridan Baker puts it best when he says that overusing em dashes is a “sign of ignorance, or of laziness.” In Woe is I, Patricia T. O’Conner says that too many em dashes signify unclear thinking: “[W]hen thoughts are confused, it’s easier to stick in a lot of dashes than to organize a smoother sentence.” So don’t give the critics of the em dash more fodder; after using an em dash, take a break for three or more sentences before using another one.
  • Don’t call one or two hyphens an em dash. Novices take the hyphen shortcut, perhaps assuming that their readers won’t notice the difference. Typing two hyphens was a common way to indicate an em dash when lawyers used typewriters. But modern word-processing programs can directly insert an em dash into a document. In Microsoft Word 2010, you can insert an em dash by selecting the Insert tab and then the Symbol subtab. If you have a Mac with Word, you can insert an em dash by simultaneously pressing the Option + Shift + Hyphen keys.

Em dashes add energy, variety, polish

Now that you know the basics, consider trying out the versatile em dash. You’ll find that the em dash adds energy—and much needed variety—to your prose. The em dash also gives you another option when the standard commas, parentheses, or colons don’t quite strike the desired tone. Like a carpenter with precision tools, em dashes will polish your prose and make your legal writing stand out from the mediocre.

This column is adapted from an article originally published in the Minnesota Lawyer on July 1, 2013.


  • 2013-07-13. Originally published.
  • 2014-10-22. Republished.


  1. Avatar ptd says:

    In both Mac and Windows Word, the program will auto-format two hyphens into an em dash. To have it work, you need to connect the dashes to the words preceding and following the hyphens.
    In other words, “preceding–following” will format into “preceding—following.” This is much easier than hunting for it in the insert menu…

    • Avatar Sam Glover says:

      One of my favorite things about my Mac is how easy it is to type en dashes (Option+hyphen) and em dashes (Option+Shift+hyphen) anywhere I want them. There’s no need to rely on Word’s autocorrecting, which isn’t present in other programs.

      For Windows and everything else, check out Copy Paste Character, which makes it easy to access special characters, including dashes.

    • Avatar Matthew Salzwedel says:

      ptd, you’re right. It’s another reason why there’s no excuse to avoid the em dash. You can also set up a shortcut key for it (and the en dash, too).

      I use Ctrl + Shift + Alt + hyphen for the em dash and Ctrl + Shift + hyphen for the en dash.

      • Avatar Guilford_guy says:

        Actually, when using Word for Windows, you can use Ctrl-Alt-hyphen [on number pad] to get the em dash, and Ctrl-hyphen [on number pad] to get the en dash. It only works with the hyphen on the number pad, not the main keyboard. No need then to set up a shortcut key as Matthew has done.

        • Avatar TRex:ex says:

          Thanks for the tip about the en dash. I learned something new. In Word I have always used Ctrl+Alt+hyphen on the keyboard for the em dash, but I didn’t know Ctrl+hypen produced the en dash. I have always produced the en dash by Alt+0150 on the keyboard locked. By the way, you can produce the em dash by Alt+0151 on the keyboard locked.

  2. Avatar Angela says:

    Does anyone know how to insert an em dash on an iPhone?

  3. Avatar Tom Bentley says:

    Having written a couple of essays on punctuation, I loved this post. (It’s quite “dashing,” you might say.) And knowing that there’s a “Typography for Lawyers” book makes it even better. Thanks.

  4. Avatar Sam @ SmithSEO says:

    As a Chicago Manual–trained editor who has recently turned to editing legal docs, I wonder if anyone can offer me any tips on using the EN dash in legal writing? Chicago limits the en dash to compound phrasal adjectives (as in phrase the “Chicago Manual–trained” above) or number ranges. Matthew Salzwedel, when can we expect your column on “The Enigmatic En Dash”?

    • Avatar Lucy says:

      The only use we make of an en dash at National Legal Research Group is, per Bluebook, to use it (or a hyphen) to separate inclusive page numbers, e.g., 87 Yale L.J. 1057, 1065–69 (1978); in other words, we use an en dash with a number spread where one would otherwise use the word “to” or “through.”

      Unlike Keith’s experience above about the ease of conversion, we have found the conversion to MS Word from WordPerfect of either the en or the em dash (or the § or the ¶) bothersome: We have to replace each and every symbol in the MS Word conversion with the alt keystrokes to ensure that the resulting symbols show up correctly—and not as a capital C or something—on the client’s computer.

  5. Avatar Randall Ponder says:

    This is an excellent overview of the issues surrounding the em dash. Matthew hits on the all of the major issues surrounding this useful ? but needed ? item of punctuation. Thank you Matthew. Randall Ponder, Baton Rouge, Louisiana. Author, Editor, Legal Projects.

    • Avatar Bo says:

      You didn’t use the em dash, you used a hyphen. Notice the difference: “surrounding this useful – but needed – item of punctuation.” vs “surrounding this useful—but needed—item of punctuation.”

      • Avatar Randall Ponder says:

        Good catch Bo. In my haste, I inserted an “en dash” (not a hyphen). The style books are divided on the issue, but I occasional insert spaces before and after the em dash, although no spaces are usually preferred. Thanks. Randall

  6. Avatar Keith says:

    Alt+0151 will create an EM dash without having to insert special characters. —. Even worked on this blog response.

    • Avatar Sam Glover says:

      I’ve “known” this for years, but I’ve never gotten it to work. I don’t know what I’m doing wrong, but I have never been able to successfully use an alt code. I’ve gotten lots of advice, and tried all of it. Maybe all my Windows-based PCs have been broken, or something (although I doubt it).

      Even if they do work for you, they are hardly user-friendly.

      • Avatar Keith says:

        While it takes more key strokes, the unicode (Alt+0151), seems to work for me on any word processing or writing application that is running on a windows PC. I often find myself using, at times, MS web apps, Google drive, Open Office/Libre office, Notepad, Wordpad, Abiword and others. Not all these programs have a special character insertion ability. Using the unicodes for ¶, §, —, ¢, and more, means I only have to know a dozen codes regardless of the writing program. The character also seems to transfer without issues, if you convert from one document type, (.doc, .odt) than “inserted” characters.

        • Avatar Sam Glover says:

          Hey, I just got it to work! I had to use my numpad to do it, though. Using the number row doesn’t do anything. Since only one of my four computers has a numpad, and it’s the one I use least often, this does me no good.

          • Avatar Richard says:

            Late reply . . . . but trying anyway. Some Windows laptops have the numpad on the keyboard as alternatives to the standard keys. You access these alternative keystrokes through the “fn” key. Still kind of cumbersome to type because you have to hold down one more key (fn + Alt + 0151) to make the numbers work instead of the letters.

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