Sometimes it’s like trying to figure out Morse code, with all its dots and dashes. You have a hyphen, an en dash and an em dash. The big three crop up all the time in writing but let’s face it, most of us don’t know why. As a result, we use them inconsistently and incorrectly.
It’s easy to do. Each one is a horizontal line of varying lengths. It’s important to understand, however, that these three different marks have three distinctly different purposes. Using an en dash to do the work of a hyphen is as much an error in punctuation as sending a question mark in to do a comma’s job.
Here are the rules for using each one:
Hyphen: This is the shortest mark and is used to connect two things that are intimately related. Usually, they connect compound words (like go-between or cinder-block) that function together as a single concept or work together as a joint modifier. Hyphens also are used to divide words that break at the end of a line.
En dash: The en dash gets its name from the letter N on the keyboard as its width is the same as that of small n. It connects things that are related to each other by distance, as in the May–September issue of a publication. In fact, these dashes specify any type of range, which is why they properly appear in indexes when a range of pages is cited (e.g., 147–48). En dashes are also used to connect a prefix to a proper open compound, such as pre–World War II. In this example, “pre” is connected to the open compound “World War II” so it has to do a little more work to bridge the space between the two words it modifies.
Em dash: This dash has a length equal to the width of the letter M. It’s used primarily for punctuation in the English language. The thing to remember is that there aren’t any spaces before or after it. It’s also used in a sentence to indicate a long pause.
Similar to parentheses, an em dash allows another thought to be added to a sentence by breaking away from that sentence—like I’ve done here. These dashes also substitute for something that’s missing. For example, in a bibliographic list, rather than repeating the same author over and over again, three consecutive em dashes (also known as a 3-em dash) stand in for the author’s name. In interrupted speech, one or two em dashes may be used: “I wasn’t trying to imply——” “Then just what were you trying to do?” It can serve as a type of bullet point, too.
Em dashes also:
- Work better than commas to set apart a unique idea from the main clause of a sentence: “Sometimes writing for money—rather than for art or pleasure—is really quite enjoyable.”
- Separate an inserted thought or clause from the main clause: “I can’t believe how pedantic Ken is about writing—I mean, doesn’t he have anything better to do?”
- Show when dialogue has been interrupted: “I reached in and pulled the spray can out of my pants—” “In front of the police?”
A little trivia about dashes
Why don’t most people use dashes correctly? Wasn’t anyone paying attention in English class?
It’s safe to say we can blame typewriters and computers for changing how we use punctuation.
These dashes go back to an earlier printing era when metal blocks that imprinted each character were used). Later, in the days of the typewriter, there was only the hyphen. Two dashes were used for the em dash and “space-hyphen-space” as a rough replacement for an en dash. Computers brought this level of detail and flexibility to the masses. Now we all can use dashes like a professional typesetter.
How do you use dashes and hyphens in your writing? Do you have any questions or thoughts to add about punctuation marks in general?