The Ins and Outs of Em Dashes and En Dashes

Based on that headline, if you’re still reading this you either have little else to do right now or are really a grammar geek. Congratulations either way.

You have to be pretty geeky to talk enthusiastically about em dashes and en dashes, but they can be put to good use—if used properly—in your communications. (In particular, I’m a big fan of the em dash—the longest mark in the “family” of punctuation that comprises em dashes, en dashes, and hyphens.)

An em dash derives its name from being the approximate width of a capital M. It can function like a comma, parenthesis, or colon. Like commas and parentheses, em dashes often set off descriptive or parenthetical information. And like a colon, it can introduce a word or a clause that describes or expands upon what precedes it.

As for spacing around em dashes, it varies widely. University Relations’ style calls for no spaces between em dashes and the text that precedes and follows them, but many newspapers and magazines add a space.

Here are just a few examples of how em dashes can be used:

Em dashes are often used—like commas and parentheses, and this helpful aside—to set off parenthetical information within a sentence. They’re often used to highlight lists of things when commas would be unwieldy.

• After excelling in an assortment of challenging courses—physics, organic chemistry, and physiology—Lee decided to pursue a career in medicine.

The em dash can be used to indicate a sudden change in direction within a sentence.

• Most experts outside of the program felt this would be a rebuilding year for the Gophers, but Coach Clippard—she knew otherwise.

They can be used to expand upon the previous clause in a dramatic way.

• Stella would never forget the call she received that snowy evening in December. It was her daughter sharing the news she had hoped to hear—Rachel had been accepted to the University of Minnesota.

An em dash can introduce a summary statement following a series of terms or phrases.

• Village Wok, the Big 10, the iconic two-story McDonald’s—the list of food joints squeezed out for more high-rise housing units kept growing.

An em dash can precede the source in a pull quote:

• “I would say 10-12 years ago we recognized that this broader lens of wellbeing was what people are really yearning for in their life.”
  —Mary Jo Kreitzer

And when em dashes are setting off material that requires a punctuation mark like a question mark or exclamation point, that comes inside of the final dash:

• “When spring arrived—finally!—frustrated Minnesota gardeners were able to get their fingers into the ground.”

A quick word on en dashes

En dashes, named because they’re the width of a capital N—go figure!—are seldom used, presumably because most people don’t know how to create them (Option key + hyphen on a Mac keyboard; Alt + 0150 on a PC), and I scarcely recall seeing them in University publications or on websites in recent years. Most people use simple hyphens in their place.

Here are two great uses for en dashes that offer more clarity and make for easier reading:

They can be used between numbers and dates to signify the meaning “up to and including.”

• The patio will be open May 1–September 30.
• The Bookstore’s hours of operation are 8 a.m.–6 p.m.

En dashes are also used in lieu of a hyphen in compound adjectives when one of the elements is a two-word compound.

• She rose to power in the post–Cold War era.
• They all took advantage of internships with Twin Cities–based 3M.

One final note. Both em and en are perfectly good words in Scrabble, but if either of those is your primary word, you’re having a tough turn.

Source: ‘A Guide to Em Dashes, En Dashes, and Hyphens’ on merriam-webster.com