When and How to Use a Dash in Writing

Used to Interrupt, Introduce, Repeat, Separate & Clarify Sentences

Dec 25, 2008
Megan B. Wyatt

A long (em) dash - decodeunicode

A dash is often found in writing, but what exactly is the purpose of a dash, anyway? Here's where you can find everything you need to know about dashes.

Dashes are frequently used and found in books, articles, and academic writing, but they are often misused. A long dash (or em dash) is used in sentences, and a short dash (or en dash) is used to mean between, through, or to.

A dash or set of dashes is used to introduce a change or interruption in the thought or tone of a sentence, to introduce an afterthought or summary at the end of a sentence, to repeat a word or phrase for emphasis, to separate a phrase for clarity, or to indicate a series of numbers or letters.

Using a Dash to Interrupt

In writing, an interrupting thought or explanation, sometimes an appositive, can be punctuated between dashes.

My boyfriend—the most humble guy around—deserved the recognition.
Run to the store—if it's not a problem—while I pick up the kids.

Using a Dash at the End of a Sentence

A dash can be used at the end of a sentence to introduce an afterthought or a summary of part of the sentence. This kind of dash serves the same function as a colon, and in formal writing, a colon should be used instead of a dash.

Mandy searched everywhere for her most prized possession—her grandmother’s wedding ring.
It’s important that y’all are at tomorrow’s rally—each and every one of you.

Using a Dash for Appositives and Clarity

When appositives contain a list set off in commas, using a set of commas to set off the appositive can become confusing for readers. Using appositives in place of the commas will help keep the reader focused on the sentence and not its punctuation. Dashes can also be used in place of commas to emphasize the word or phrase.

Her five children—Krista, Kelsy, Morgan, Seth, and Jason, have all moved out.
The police arrested the suspect after receiving an overwhelming amount of evidence—five witness reports and his ID card—against him.

Using a Dash to Indicate a Set of Numbers or Letters

One of the most common and everyday uses of the dash is to indicate a series of numbers or letters.

Next class, everybody whose name ends in P-Z will do his or her project.
Women between the ages of 13-25 are at the highest risk for developing an eating disorder.

Remember that dashes are generally used as an interruption or sidenote in writing. Dashes are sometimes used frequently in blogs and informal writing as a speaking or interrupting stream-of-consciousness style. In more formal writing dashes have the same function, but the interruptions do not have the same conversational or commenting sound and tend to be a side fact or explanation.