Is it just me, or has writing really started to resemble Morse Code? Lately, writers have been using dashes instead of commas, semicolons, colons, parenthesis, and just about every other punctuation mark in the grammar arsenal. It may be the modern writer’s new weapon of choice, but is the dash really a cure-all that deserves to wipe all our tried-and-true punctuation marks off the face of the Earth? Or, is it just a convenient little line that does our grammatical dirty when we’re too lazy to think about what punctuation works best? In short, don’t let it be the grammar bully.
Writer, here’s a quick rundown of when you should—and should not—employ a dash. (That just then was a “should” instance.)
Here’s when to use the em dash.
The em dash, named as such because it’s roughly the length of a letter “m,” is used to illustrate an interruption, an abrupt change of tone or thought, or to add emphasis.
These call for the em dash:
I need you—only you—in my life.
I never believed in love—until I found you.
I think we’ve run out of—oh, never mind.
The general rule for formal writing goes like this: use the em dash as sparingly as possible. Sure, it’s tempting to use dashes instead of colons (“I’ve run out of three things—margarine, flour, and brown sugar”) or commas (“My friend—Sam—has a kind heart”), but unless you want to convey informality or have a true grammatical reason for doing so, try to resist the urge.
Here’s when to use the em dash’s truncated cousin, the en dash.
You guessed it: the en dash gets its name from being about the width of a letter “n.” The en dash is commonly used to indicate a range (pages, ages, scores, etc.), or if you run across an open compound adjective.
I only need 2–3 more hours to finish this assignment.
Did you see the Census date they just released for 1931–1940?
I love learning about Cold War–era politics.
(Use an en dash because “Cold War” is two words; use a hyphen in a simple, two-word compound like “Revolution-era.”)
Here’s when to stick with the hyphen.
Regardless of what your high school English teacher told you, a hyphen is not the same as a dash. It’s used to connect two words in a compound adjective, noun, verb or adverb, or to avoid ambiguity or confusion.
I can’t find my favorite T-shirt.
Did you just see that man-eating shark?
I love learning about Revolution-era politics.
Most grammar authorities say that you should avoid using em dashes in formal writing unless the sentence truly warrants them. If your em dash could be swapped out for a comma or colon, do so. Why interrupt your sentence’s flow unless that’s your true intention? And on an ending note, remember that you shouldn’t insert spaces between your words and dashes. That’s all—for now, at least!