Getting to Know the Em Dash

As we mentioned in our recent post about the hyphen, the en dash and the em dash are two of the most misunderstood punctuation marks in English. How should you use them? The en dash is primarily used in continuing numbers or dates taking the place of “to” or “through,” as in “The festival will be held from May 2–4.” The em dash is an incredibly versatile punctuation mark that can be used in lieu of parentheses, commas, colons, or quotation marks or to signal an interruption or amplification of an idea.

When Vulture pointed out some of the best punctuation marks in literature, they cited this sentence from George Eliot’s Middlemarch: “One morning, some weeks after her arrival at Lowick, Dorothea—but why always Dorothea?” Here the narrator is so distracted by the attention reaped on Dorothea that she interrupts her sentence with a rhetorical question. F. Scott Fitzgerald also relied on the em dash, particularly in The Great Gatsby: “I lived at West Egg, the—well, the less fashionable of the two, though this is a most superficial tag to express the bizarre and not a little sinister contrast between them.”

Why are they called en and em dash? The names come from typography—the work of setting, arranging, and printing types. An em is a unit of measurement defined by a capital M in the typeface being used, thus an em dash is a dash that is the width of an M. An en is half of an em and bears no direct relation to the size of the capital N. (In antiquated typography slang, an en was also frequently called a nut or a molly, to clearly distinguish it from an em.)

The debate about the merits and potential abuse of the em dash rages. Back in 2011, Slate inveighed against the em dash, claiming that it was being overused, leading to sloppy prose. Then in 2012, Ben Yagoda extolled the virtues of the em dash in a blog at the New York Times.

Our editors have noticed the hyphen, double hyphen and minus sign encroaching on the territory of the em dash with increasing frequency in recent years. In the massive digitization project, Google Books treats hyphens, en dashes, and em dashes as the same character, translating them all into “–”. Neither the en nor the em appear on standard keyboards making them even harder to use. In order to find an em dash in Google Docs, a user must navigate through the Insert menu into Special Characters, though the Punctuation drop down and finally into Dash/Connector to find the lowly em dash: —. (Of course the dash-conscious typer could always memorize the keyboard shortcut.)

Conversely, Microsoft Word automatically translate a hyphen into a double hyphen), but this does not mitigate the risks of an em dash in the wild. An exacerbating factor may be that using non-standard characters (like the en dash and the em dash) risks corrupting the text because many platforms do not use the same character standards (see Google Books above). The conscientious web editor might now purposely avoid the elegant em dash out of fear that it will display as the dreaded ? on em-dash incompatible sites or devices.

Do you often use the en and em dash? What do you think about them?