Dashes are not a one-size-fits-all answer each time you need to pause.
People frequently use dashes interchangeably with the comma: Anytime they want to pause, they just toss in dashes without realizing that the nature of the information dictates whether a dash is appropriate. The comma represents a routine pause; the dash does not. You can occasionally use a dash in place of a comma or parentheses, but a dash typically signals an interruption, and it focuses a reader’s attention.
Here are common situations where you might use a dash:
To break the thought, usually for emphasis
It sets off words that you want to accent, usually because it’s important or unusual information.
What needs to happen first—and I will insist on this—is that we have to design a strategy
Just turn the lights out when you leave–and don’t forget to lock the door.
To indicate a shift in thought or tone
The details of the proposal–remind me to fill you in–were impressive.
She wants me to serve on the advisory committee–I have no interest whatsoever–so I need to meet with her.
His creative idea–if that’s what you call it–will be on Friday’s agenda. (The tone in midsentence shifts to sarcasm.)
To accent introductory elements (words that don’t contain the subject and are not part of the main thought).
Enthusiasm, knowledge, experience, sensitivity—these are the qualities we are looking for.
Speed, agility, strength, mental sharpness—if you don’t have those, forget it.
To set off a list
Her last day on the job, she packed her memories—awards, autographed ball, books pictures, books.
I can only imagine what I have to look forward to on the hike–cold, rain, hunger, and exhaustion.
If information in a given sentence requires more emphasis than a comma or parentheses provide, then use it, but don’t use dashes excessively. It will dilute their impact. When another mark can fit, use it.
If you could benefit from more writing tips, join us for a webinar September 8th, called “Influencing Your Audience: Crafting Messages that Motivate.” Learn subtle persuasion techniques to use immediately, even in email, to make your messages convincing.
Ken O’Quinn is a professional writing coach and former Associated Press writer who conducts corporate workshops on business writing, persuasive writing, and corporate communications writing. He is the author of Perfect Phrases for Business Letters (McGraw-Hill), which is available here at Amazon.com.