The Grammar Mechanics of Writing - Em Dashes, En Dashes, and Hyphens
I want to keep talking about the power of punctuation in fiction, and try to show how important it can be to a reader’s understanding of the prose. After all: choosing the right punctuation will enhance a reader’s experience, drawing them further into the story.
Since punctuation is such a powerful tool for writers to employ in their storytelling, I’m going to continue this series with another piece of punctuation I often see misused or overused by authors—em dashes. But in order to talk about em dashes, I feel we also need to address em dash’s family, the en dash and hyphen.
A note: The Chicago Manual of Style (CMOS) is a writer’s or editor’s best tool for understanding grammar in fiction. Most publishing houses utilize CMOS as the standard style guide for all publications they produce, along with in-house style guides. I’ll be utilizing definitions from this guide throughout our discussion on em dashes, en dashes, and hypehns, using its guidelines as the industry standard.
On a specific note: these rules may change over time. As new technology emerges and generations move on, language tends to evolve along with it. The CMOS is usually timely in its adjustments to these kinds of changes, but the best way to be aware of industry-wide changes to grammar rules is to read widely in the genre you’re writing or editing.
I’m going to start our discussion by specifying the differences between em dashes, en dashes, and hyphens and their uses in prose. Then we’ll go through the rules for using each in prose.
The em dash (—) is the most common of the three in prose, and the most versatile. Merriam-Webster says it “can function like a comma, a colon, or parenthesis.” They’re used to set off necessary information in the midst of a sentence, or when a character’s speech is cut off by another character and/or revelation. Essentially, it’s used when there’s an interruption to the prose. It’s the longest of the three, about the width of an “m”.
The en dash (–) is “a shorter dash that has special significance in certain types of compounds and in number ranges” (CMOS 2.17). These aren’t often used in fiction; they’re far more common in nonfiction dealing with dates and number ranges. It’s easy to confuse with the em dash, but is usually shorter, about the width of an “n.”
The hyphen (-) is most often used in prose for compound words. More recently, they are also used to denote a swear word without spelling out the word.
Em Dash
As the most common within prose, I’d like to discuss rules for the em dash first. CMOS calls it the most versatile, and it’s often just referred to as the dash. However, it’s easily overused in prose (I’m guilty of this in my own writing 😅). Ideally, you don’t want more than three em dashes per page of prose (approx. 250 words). There should also be no more than two em dashes in a sentence.
Although an em dash can take the place of a comma, that doesn’t mean it should.
CMOS 6.91: “Em dashes are most often used to set off an amplifying or explanatory element. In that sense they can function as an alternative to parentheses, commas, or a colon—especially when an abrupt break in thought is called for. An em dash can also be used in lieu of a period or semicolon.
To avoid confusion, the em dash should never be used within or immediately following another element set off by an em dash (or pair of em dashes); use parentheses or commas instead.”
Use to set off an amplifying element:
*The odd floating television in the air conjured by the pillar of darkness that was so amused—Mire.
Use to set off an explanatory element (in lieu of parentheses):
*But the only scene this place occupies is the beginning—Genji and I meeting here to talk—and the very end, when I found myself sitting on the bench, the space next to me empty.
Use to set off an explanatory element (in lieu of commas):
*They can’t hunt down a kidnapper who has no name or face—and leaves no trace.
It’s him—Genji—and yet…
In lieu of a colon (not often used in prose):
It was a revival of the most potent image in modern democracy—the revolutionary idea.
Use as an abrupt break in thought, in lieu of a period (most often in dialogue):
*I remain as still as I can, but the slope of those shoulders, the tilt of the head—
CMOS 12.42 defines this further for dialogue: “To show an interruption to quoted speech or dialogue, an em dash is normally used. As with question marks and exclamation points, which take the place of commas and periods at the end of quoted speech, the dash alone signals the end of the speech.”
*“I promised I’d never leave you alone and—”
CMOS 6.93: “An em dash or a pair of em dashes may indicate a sudden break in thought or sentence structure or an interruption in dialogue.”
“Will he—can he—obtain the necessary signatures?” asked Mill.
They can also be used to sparingly add body language or character thoughts in the midst of a character speaking.
CMOS 12.42: “Normally, the dash belongs to the interrupted speaker and is placed inside the quotation marks. But when the narrator intervenes in the middle of a speech, the dashes are placed outside the quotation marks, even if the speaker’s words are themselves interrupted.”
*“Genji”—his eyes light up and he leans forward again—“I got back a year ago.”
As noted earlier, the em dash is quite versatile, and it’s a powerful piece of punctuation for authors. I do want to note that, although the recommendation is to keep em dashes to two or fewer on one page, if you have characters constantly interrupting each other (often within an argument), you can have a few more. Just use your discretion, but try to use them sparingly. The more often you use them, the more visible they’ll be to the reader.
En Dash
Since it’s not often used in prose, I’m not going to touch much on the en dash, but I wanted to include it here. According to CMOS 6.89, it’s often used in British English in place of the em dash (and some other publishers may use the British version).
CMOS 6.83: “The principal use of the en dash is to connect numbers and, less often, words. With continuing numbers—such as dates, times, and page numbers—it signifies up to and including (or through).”
The years 1993–2000 were heady ones for the computer literate.
For source citations and indexing, see chapters 13–15.
Join us on Thursday, 11:30 a.m.–4:00 p.m., to celebrate the New Year.
But—“For the sake of parallel construction, the word to or through (or until), never the en dash, should be used if the word from precedes the first element in such a pair; similarly, and should be used if between precedes the first element.”
She was in college from 2019 to 2022. (not from 2019–22)
He usually naps between 11:30 a.m. and 1:30 p.m. (not between 11:30 a.m.–1:30 p.m.)
Also: “In other contexts, such as with scores and directions, the en dash signifies, more simply, to.”
The London–Paris train leaves at two o’clock.
On November 20, 1966, Green Bay defeated Chicago, 13–6.
CMOS 6.85: “When the names of two or more people are used as a compound modifier before a noun, an en dash rather than a hyphen will help to clarify that the compound name belongs to more than one person.”
the Ali–Frazier match (a match between Muhammad Ali and Joe Frazier)
Epstein–Barr virus (a virus named for Anthony Epstein and Yvonne Barr)
the Mason–Dixon line (named for Charles Mason and Jeremiah Dixon)
Hyphen
The last one I want to touch on is the hyphen. These can be quite tricky, and I’ve found a lot of editors overuse them when it comes to compound terms. The thing is, some do require the hyphen, while others do not—whether because they should be two words or one word. As CMOS suggests, I strongly urge authors to check these possible hyphenated words with the dictionary first (Merriam-Webster is my go-to).
CMOS 7.87: “Far and away the most common spelling questions for writers and editors concern compound terms—whether to leave them open, hyphenate them, or close them up as a single word. Prefixes (and occasionally suffixes) can be similarly troublesome. The first place to look for answers is the dictionary … [for those] spelling compounds not necessarily found in the dictionary … treat compounds according to their grammatical function (as nouns, adjectives, or adverbs) and their position in a sentence.”
CMOS 7.96: “In general, Chicago prefers a spare hyphenation style: If no suitable example or analogy can be found either in this section or in the dictionary, hyphens should be added only if doing so will prevent a misreading or otherwise significantly aid comprehension.”
I know this can be quite confusing, so I’ve included several examples below:
Age - “Hyphenated in both noun and adjective forms (except last two examples)”
a seventeen-year-old (man, woman, etc.)
a group of 18- and 19-year-olds
but
nine years old
20 years of age
Colors - “Hyphenated before but not after a noun”
blue-green eyes
green-and-white print
but
his eyes are gray
the truth isn’t black and white
Compass Points & Directions - “Closed in noun, adjective, and adverb forms unless three directions are combined, in which case a hyphen is used after the first. When from . . . to is implied, an en dash is used.”
southwest
north-northeast
a north–south street
Probably the trickiest hyphen or no hyphen decisions are dependent on parts of speech in a sentence. There are several of these combinations, but I’ve only included the ones where I see writers struggle most often. Here’s what CMOS says about these:
adjective + noun - “Hyphenated before but not after a noun.”
Ex: a high-quality carpet or a top-ten school but the neighborhood is middle class.
adjective + participle - “Hyphenated before but not after a noun. Some permanent compounds are closed; check Merriam-Webster.”
Ex: a tight-lipped person or an open-ended question but a lighthearted conversation or the question was open ended.
adverb ending in -ly + participle or adjective - “Open whether before or after a noun.”
Ex: a highly paid person or he was mildly frustrating.
adverb not ending in -ly + participle or adjective - “Hyphenated before but not after a noun; certain compounds, including those with more, most, less, least, and very, can usually be left open unless ambiguity threatens. When the adverb rather than the compound as a whole is modified by another adverb, the entire expression is open.”
Ex: a much-needed addition or the best-known author or the most-skilled workers (most in skill) but a less prolific artist or it was much needed or a very much needed addition.
noun + adjective - “Hyphenated before a noun; usually open after a noun.”
Ex: computer-literate authors or fan-friendly stadium but she is world famous or the stadium is fan friendly.
noun + gerund - “Noun forms usually open; adjective forms hyphenated before a noun. Some permanent compounds hyphenated or closed.”
Ex: a mountain-climbing enthusiast or a Nobel Prize-winning chemist but mountain climbing.
Ex: head-hunting or decision-making but bookkeeping or caregiving or copyediting.
noun + noun, single function (first noun modifies second noun) - “Noun forms open; adjective forms hyphenated before a noun.”
Ex: tenure-track position but tenure track.
noun + noun, two functions (both nouns equal) - “Both noun and adjective forms always hyphenated.”
Ex: writer-director or city-state or city-state governance.
Again, if in doubt, reference the dictionary first. This is always my go-to when I’m questioning whether or not a hyphen is needed. If I can’t find my answer there, I turn to the Chicago Manual of Style’s rules.
Some Closing Comments
Punctuation is often tricky for authors, and that’s okay. That’s what we have editors for, but it can be nice to understand where your editor is coming from when they make a punctuation change. What we all need to remember is a grammar-loving reader will notice if the punctuation is used incorrectly. The biggest problem that arises from this is it’ll distract the reader from the story itself, leading them to focus on punctuation instead. It may also cause them to DNF (Did Not Finish) the book and leave low-star reviews.
Of the three types of punctuation we discussed today, I find em dashes the most useful in fiction. They’re incredibly versatile, and they’re a wonderful way to leave readers hanging, asking “what’s next?” and leading them to read on. (But please, please keep in mind they’re easily overused.)
If used correctly in storytelling, punctuation can greatly enhance a reader’s experience and understanding of the story and characters.
Again, I want to warn that this shouldn’t be a worry during the writing process—wait until your self-edit phase to nitpick at your dashes and hyphens. Or, if you’re simply confused by all of the different rules and exceptions, hire a good copyeditor to fix those em dashes and hyphens for you.
*Examples marked by an asterisk (during the em dash section) are from my short story Mired in Despair, available for free here.