The Em Dash: A Survey
Despite its proliferation in modern texts, the em dash is not present in the majority of early writing curricula. It is one of the most versatile punctuation marks in the English language, with many different functions and the ability to act as an alternative to a number of other marks, but, though most can likely recognize it on sight, few English readers would be able to identify it by name. Its absence in education is likely due, in part, to its rocky past, as well as to the unflattering whims of public opinion, which now seem to be shifting. As the em dash returns to favor, it is worth exploring the history and merits of this valuable punctuation mark.
The Chicago Manual of Style describes the em dash as “the most commonly used and most versatile of the dashes” (333). It is most often used to “set off an amplifying or explanatory element,” and, in this way, can take the place of a comma, a semicolon, a colon, a pair of commas, or a pair of parentheses (333–334). Though the em dash can be mechanically interchangeable with these other marks, it carries a different tone. For example, it tends to be read as less formal, particularly compared to the colon and semicolon (Norris 145–146); when it comes to paired punctuation used to set off an interruption, em dashes emphasize the contained information, while parentheses deemphasize it, and commas, read as neutral, do not act on it at all (Einsohn 89). Because the em dash is effective in so many contexts, it is prone to overuse; it should be employed carefully and sparingly. Einsohn states that, especially when taking the place of a semicolon in joining independent clauses, it “is best reserved for special effects” such as “prepar[ing] readers for a punchline or a U-turn” (81).
The em dash has other purposes, as well, including some that only it can fulfill. It is commonly used to indicate an interruption or other sudden break, particularly in dialogue; in this role, it can be placed at either the end or the beginning of a thought, to indicate that the thought is being either cut off or picked up partway through (Norris 135). It is used to lend a sort of breathless urgency to writing (136) and to represent stream-of-consciousness thinking (Truss 158); it is effective in setting certain tones, and has, thus, been a popular punctuation choice for poets, including Emily Dickinson (Norris 137–138). In playwriting, the em dash is also employed to “secure suspense” and emphasize a word or phrase at the end of a sentence (Smiley and Bert 206–207). More technical uses include the replacement of bullet points in lists and the replacement of quotation marks in dialogue, particularly dialogue translated from a language that prefers guillemets over quotation marks (The Chicago 335).
In order to fully understand the em dash, one must first understand the em. The Chicago Manual of Style defines the em as a “unit of type measurement equal to the point size of the type in question” (895), meaning that, in a twelve-point font, the em—and, therefore, the em dash—will be twelve points wide. It is largely accepted that the em is so titled because it is the width of a capital letter M (“Glossary of Typographic”); while this may have been true at one time, it is not reliably true now, as the M in most modern typefaces is narrower than the em. In fact, the length of the em cannot be measured by any text seen in print or on screen: It is the height of the type, which comprises the character and a small space used as a buffer between lines of text—the leading. In the days of metal type, each piece of type would include a narrow piece of lead at the bottom of the letter or mark; the height—and, therefore, the em—includes this leading and the negative space created by it (Phinney).
The etymology of the em dash, though not relevant to its proper usage, is interesting. It is named for the em, of course, because it is the length of one em; the word dash, though, is more intriguing: Dashes, as a group, were likely given this title because of the action used to create them. “Dash” comes from the Middle English verb dasshen—to knock, to hurl, to break (Truss 159)—and means “to strike violently”; dashes were used in handwritten text even before the age of metal type, and were produced with a sharp dash of a pen on paper. Though usage of the dashes as punctuation marks has evolved over time, this definition has been in evidence since the middle of the sixteenth century (Houston 150).
Variations on the em dash exist in certain contexts. In the past, the em dash was often paired with other punctuation marks, forming such creations as the comma-dash or “commash”; though these “dashtards” were, at one time, employed by writers as venerated as Shakespeare, they have been considered nonstandard for over half a century (151–153). In British writing, the em dash is itself nonstandard; in its place, a spaced en dash is used (145). There are also 2-em and 3-em dashes, which have their own purposes and are, respectively, two and three ems long. The 2-em dash is used to omit words or parts of words, such as names or expletives, or to represent missing or illegible information in quoted text (The Chicago 335–336). It was regularly employed to censor names of politicians in mid–eighteenth century England, in order to circumvent a ban on parliamentary reporting (Houston 158–160), but has since fallen out of style; at that time, it was also so commonly used to censor expletives that the word “dash” itself became a mild epithet (158). The 3-em dash, meanwhile, is used in scholarly bibliographies, to indicate that the author or editor of an entry is the same as that of the previous entry (The Chicago 336).
Since the days of metal type, the em dash has had a rocky history. Though it was common enough during and prior to that era, it saw a decline when Christopher Latham Sholes patented the first typewriter in the 1860s. Due to spatial limitations and the lack of a shift mechanism, Sholes’s QWERTY keyboard had to prioritize certain characters over others; there was only room for one dash, and Sholes chose a version of the hyphen (Houston 160–161). The hyphen, then, had to act for all dashes—it entirely took the place of the en dash, and in order to create the em dash, typists would have to type two hyphens in a row. Modern word processors now have helpful shortcuts for typing the em dash, and will even autocorrect a double hyphen into an em dash, but the remnants of this reliance on hyphens can be seen in comic books, where it is still lettering practice to use the double hyphen instead of the em dash (Klein).
The em dash has also experienced shifts in attitude; as with all aspects of the English language, it has both its proponents and its detractors, but there have been clear trends in its popularity. Its informality and versatility were, at one time, viewed as drawbacks; as Norris explains, “[t]he sheer range of its use suggests that it’s a lazy, all-purpose substitute for more disciplined forms of punctuation” (136). Truss similarly describes how it was “seen as the enemy of grammar” because it is so prevalent in email and texting communication, which are often characterized by “overtly disorganized thought” (157). Norris also notes that women often use em dashes (136), which is, in itself, an explanation for the contempt it has faced, since things used and enjoyed by women tend to be derided in modern society.
The em dash is, however, seeing a return to popularity, and an increase in respect. As Gopen describes, beginning in the 1960s—when using the em dash would have gotten him “sent straightaway to the headmaster’s office to be reprimanded for [his] act of moral turpitude”—first fiction writers, and then journalists, began employing the em dash (13). As the em dash became useful to writers, it “slowly assumed a rightful place in writing,” and eventually even grammar books began to accept it (13). It is no longer disparaged—except, perhaps, by the stuffiest of grammar snobs—and this is a victory for writers, as it presents them with “better ways to send interpretive signals to their readers” (13), as has been demonstrated by the earlier comparison of different tones expressed by various punctuation marks.
The em dash is, once again, a staple of English punctuation. It is found in many genres of modern writing, and whole sections of grammar and editing texts are devoted to it. It is a valuable mark to study: Its wide variety of uses and ability to shape a text’s tone endow it with great potential when used effectively, and an exploration of its fascinating history provides insight into a range of topics, including typographic origins and political censorship. Like other punctuation marks, the em dash has endured the changeability of popular opinion, but it is currently on the rise, and perhaps, someday, this wonderfully versatile character will be considered acceptable and useful enough to be taught in middle and high school English classes.
The Chicago Manual of Style. 16th ed., Chicago, U of Chicago P, 2010.
Einsohn, Amy. The Copyeditor’s Handbook: A Guide for Book Publishing and Corporate Communications. 3rd ed., Berkeley, U of California P, 2011.
“Glossary of Typographic Terms.” Adobe, www.adobe.com/products/type/adobe-type-references-tips/glossary.html. Accessed 5 June 2020.
Gopen, George D. “A Once Rogue Punctuation Mark Gains Respectability: What You Can Now Accomplish with an Em Dash.” Litigation; Chicago, vol. 46, no. 1, Fall 2019, pp. 13–14.
Houston, Keith. Shady Characters: The Secret Life of Punctuation, Symbols, & Other Typographical Marks. New York, W.W. Norton & Company, 2013.
Klein, Todd. “Punctuating Comics: Dots and Dashes.” Todd’s Blog, 23 Sept. 2008, kleinletters.com/Blog/punctuating-comics-dots-and-dashes/. Accessed 5 June 2020.
Norris, Mary. Between You & Me: Confessions of a Comma Queen. New York, W.W. Norton & Company, 2015.
Phinney, Thomas. “Point Size and the Em Square: Not What People Think.” Phinney on Fonts, 18 Mar. 2011, www.thomasphinney.com/2011/03/point-size/. Accessed 5 June 2020.
Smiley, Sam, and Norman A. Bert. Playwriting: The Structure of Action. Rev. and expanded ed., New Haven, Yale UP, 2005.
Truss, Lynne. Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation. New York, Gotham Books, 2004.