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center for writing | student writing support | punctuation | hyphens & dashes

Hyphens & dashes

Problem

Many writers do not differentiate between hyphens ( - ) and dashes ( – or — ), since the marks look similar. Misuse of hyphens and dashes can obscure a writer’s meaning, especially if a hyphen is used in place of a dash, or can make the writing look visually cluttered.

Solutions

Remember that hyphens ( - ) are used to combine words.

Use hyphens...

when writing out numbers from 21 to 99

incorrect
Fifty six

correct
Fifty-six

to combine the words in a compound adjective coming before the noun it modifies

incorrect
This eighteenth century manuscript is interesting.

correct
This eighteenth-century manuscript is interesting.

correct
I found this manuscript from the eighteenth century to be interesting.

incorrect
Lev Vygotsky studied the intellectual development of three year old children.

correct
Lev Vygotsky studied the intellectual development of three-year-old children.

correct
Lev Vygotsky studied the intellectual development of children who were three years old.

correct
It would be difficult to be the parent of young triplets: I can't imagine having three year-old children!

with the prefixes all-, ex-, and self- and with the suffix -elect

incorrect
Doug runs into his exwife at the grocery store all the time.

correct
Doug runs into his ex-wife at the grocery store all the time.

incorrect
That sounds like a self serving reason for volunteering.

correct
That sounds like a self-serving reason for volunteering.

incorrect
The president elect will be inaugurated in January.

correct
The president-elect will be inaugurated in January.

Learn how to make a hyphen.

In Mac and Windows systems, make a hyphen by pressing the minus key. For hyphens, you can use the one at the top of the keyboard, or you can use the one on the number pad.

 

Remember that en-dashes ( – ) have three specific uses.

En-dashes ( – ) are used (1) in place of a preposition to show a range of values, (2) to indicate relationships or connections, or (3) in rare cases, to clarify connections between certain compounds.

Use en-dashes...

to show a range of dates, times, or values

For the 2012–13 school year, Student Writing Support in Nicholson is open Mondays–Thursdays 9–4:30 and Fridays 9–2:15.

University of Minnesota Graduate Assistants rejected unionization by a 1,854–1,142 vote.

to show a relationship or connection

My O’Hare–LaGuardia flight was delayed.

I desperately want tickets for the Gopher–Badger game.

to create an attributive compound when or more of its parts is an open (non-hyphenated) compound.

This is a rare and specialized use of the en-dash.

confusing
Several journals welcome writing center-based research.
(Do the journals welcome people to write about center-based research?)

clearer
Several journals welcome writing center–based research.
(Here, it is evident that the journals welcome research about writing centers.)

confusing
I’m interested in studying the public education-charter school controversy.
(What is a public education-charter?)

clearer
I’m interested in studying the public education–charter school controversy.
(Here, it is evident that the writer is studying the controversy over two concepts that are typically expressed as open compounds: public education and charter schools.)

Learn how to make an en-dash

To make an en-dash on a Mac, press two keys: option+minus.
To make an en-dash in Windows, press two keys: control+minus on the number pad.

 

Remember that em-dashes ( — ) are used in place of other punctuation to set off information that deserves emphasis.

Em-dashes ( — ), often known simply as dashes, get their name from typography: an em-dash is about the width of the letter “m.” (Similarly, an en-dash is about the width of the letter “n.”)

Diana Hacker and Nancy Sommers (2011, p. 288) suggest three uses for em-dashes:

on both sides of material that deserves emphasis in the middle of a sentence, instead of parentheses or commas

incorrect
Tom, who has never been lucky—won the jackpot last night.

incorrect
Tom—who has never been lucky, won the jackpot last night.

correct
Tom—who has never been lucky—won the jackpot last night.

on both sides of a list in the middle of a sentence when that list contains commas

confusing
Louie stormed into the room and took four items off the desk, a pen, a paper clip, and two sheets of paper, before leaving in a hurry.

clearer
Louie stormed into the room and took four items off the desk—a pen, a paper clip, and two sheets of paper—before leaving in a hurry.

before “a list, a restatement, an amplification, or a striking shift in tone or thought” at the end of a sentence

In their 6–0 loss to the White Sox, the Minnesota Twins revealed three major weak spots—pitching, hitting, and fielding.

Student-athletes are prepared to be excellent college writers because of their high degree of coachability—persistence, self-discipline, and receptiveness to feedback are all assets for developing writers.

Every spring, Minnesotans are full of hope for warmer weather—until the inevitable late-March blizzard arrives to crush our spirits.

Learn how to make an em-dash.

To make an em-dash on a Mac, press three keys: option+shift+minus.
To make an em-dash in Windows, press three keys: control+alt+minus on the number pad.

For more information

Hacker, D., & Sommers, N. (2011).  A writer’s reference (7th ed.). Boston: Bedford/St. Martin’s.

The Chicago Manual of Style. (2010). Hyphens and dashes compared. In Punctuation. Retrieved July 16, 2012, from http://www.chicagomanualofstyle.org/16/ch06/ch06_sec075.html

Dash. (July 14, 2012). Retrieved July 16, 2012, from http://en.wikipedia.org/wiki/Dash