Drawing Lines

HYPHENS and DASHES are the most misused punctuation marks in the English language after commas, in my experience. Have you ever noticed that some writers refuse to use them, while others sprinkle them willy-nilly throughout their work without any apparent logic or reason? Many confuse hyphens with dashes, or think they are interchangeable. In fact, hyphens are not dashes and they each have specific uses.

Let’s get into it.

Why do we insert these horizontal little lines in our writing in the first place? Essentially, their purpose is to clarify phrases or sentences that would likely be misunderstood without them. If you compare the pairs of examples below, you will see how the meaning of a sentence can be changed depending on if or how hyphens or dashes are used.

The Hendersons brought their three-year-old sons to the doctor’s office. (hyphens)
(twins who are 3 years old)
The Hendersons brought their three year-old sons to the doctor’s office. (hyphen)
(triplets who are 1 year old)
My great-aunt, as well as Aunt Lucy, came to the family reunion. (hyphen)
(father/mother’s aunt plus father/mother’s sister Lucy)
My great aunt, as well as Aunt Lucy, came to the family reunion. (no hyphen)
(father/mother’s wonderful sister plus father/mother’s sister Lucy who might not be wonderful)
Small-business owners in the construction industry are often discriminated against. (hyphen)
(owners of small businesses)
Small business owners in the construction industry are often discriminated against. (no hyphen)
(business owners who are short or petite)
Her husband will discuss the check—in process as we speak—with the hotel manager. (em dashes)
(Her husband is discussing the check at this moment with the hotel manager as planned.)
Her husband will discuss the check-in process as we speak with the hotel manager. (hyphen)
(Her husband plans to discuss the process for checking into the hotel while some other individuals speak with the hotel manager.)
He attempted to re-collect his scattered thoughts. (hyphen)
(become calm and rational again)
He attempted to recollect his scattered thoughts. (no hyphen)
(remember fading thoughts)
I prefer the Monday-Friday schedule. (hyphen)
(Mondays and Fridays only)
I prefer the Monday – Friday schedule. (en dash)
(Monday through Friday)

In handwritten text, hyphens and dashes are mainly identifiable by how they are used, not by size, because of the wide variation in people’s handwriting styles. But in printed text, length matters, as well as how each one is used within the text.

Below, the hyphen and dashes are shown in order of width along with ways to insert them in your text.

Hyphen
* Use the hyphen key to the right of the number zero on the numbers row.
En Dash
* Type a word/number, type a space, type the hyphen key, type a space, type another word/number, type a space (AutoFormat inserts the en dash in Word).
* Enable Num Lock, use shortcut key combination: Ctrl plus the minus key on the numeric keypad.
* Insert > Symbol > More Symbols > Special Characters > select En Dash > Insert > Close
Em Dash
* Type a word, type two hyphens, type another word, type a space (AutoFormat changes the hyphens into an Em Dash)
* Enable Num Lock, use shortcut key combination: Ctrl plus Alt plus the minus key on the numeric keypad.
* Insert > Symbol > More Symbols > Special Characters > select Em Dash > Insert > Close
When to use a hyphen

Connecting two or more words and numbers to form one idea

absent-minded professorfull-length movie
fast-moving vehicleowner-operator of a business
six-hour drivethirty-four-year-old man
She spoke matter-of-factly about her trauma.ice-cream sandwich
over-the-counter medicinecase-by-case approach

Connecting last names of spouses (double surname)

Sarah Bennett-Johnson waved at me from across the street.
I invited Mr. and Mrs. Mendoza-Harris to the dinner party.

Connecting the ten’s place and one’s place in numbers from 21 to 99 when written as words

sixty-fiveninety-seven

Writing telephone numbers, account numbers, serial numbers, part numbers, model numbers, etc.

Call 1-800-867-5309
Product serial number: A123-B456-C789-D012

Dividing words that start at the end of one line and end at the beginning of the next line (Typically, words are not hyphenated at the end of three consecutive lines; these are hyphenated for demonstration purposes only.)

Portion of book text displaying 3 hyphenated words appearing at the end of separate lines

Signifying a missing or inferred part of a hyphenated word (suspended/hanging hyphen); *I typically try to avoid these by rewording the sentence or including two complete hyphenated words.

Fifteen- and twenty-year contracts are subject to lower fees.
She selected the highest- and next-highest-scoring groups for the final round.
The study included English- and Spanish-speaking participants.

Adding prefixes (check a dictionary if you’re not sure whether a hyphen is needed)

ex-husbandex-neighbor
extraexample
self-confidenceself-employed
selfishnessselfsame
mid-eightiesmid-Atlantic states
midnightmidsection
all-knowing oracleall-encompassing solution
They gave their all, knowing the finish line was near.allowed
re-sent (sent again)re-sign (sign again)
resent (begrudge)resign (give up, quit)
registerrespond

Creating fractions with compound adjectives

Add two-thirds of a cup of sugar.
The prize of a half-million dollars is up for grabs.

Representing the minus sign when writing negative numbers and subtracting

204=16 (AutoFormat will change the hyphen to an en dash when spaces are added, though)
5 degrees Fahrenheit
When NOT to use a hyphen (or dash)

When the modifier/adjective comes after the noun

Her students were well informed about the rules.
The house was poorly lit.

When combining an adverb with an adjective or participle

greatly anticipated event
very helpful instructions
horribly executed strategy

For open and closed compound words

Chocolate ice cream is my favorite dessert.(noun; open)
White House staff roles have been restructured.(adjective, open)
She offered to proofread my manuscript.(verb, closed)
The cover of my notebook was covered with stickers.(noun, closed)
When to use an EN dash (width of an N)

Connecting numbers or words to indicate a range, score, time period, or distance not introduced with the word “from”; replaces the word “to” or “through” (AutoFormat adds a space before and after, but they are not necessary)

These books are for children ages 5 – 8.
The Bandits won the game with a score of 10 – 9.
The Age of Enlightenment was approximately 1685–1815.
This company’s work week is Monday – Saturday.

For clarity when compound adjectives include an open compound word

Roaring Twenties–style fashion was all the rage. (no spaces around en dash)
Teachers provided some high school–level reading material. (no spaces around en dash)
When to use an EM dash (width of an M)

Before and after parenthetical and explanatory expressions

John packed all his camping supplies—tent, stove, food, dishes, and chairs—in the trunk.
The United Kingdom—England, Scotland, Wales, and Northern Ireland—is a constitutional monarchy and parliamentary democracy.

After a list that comes at the beginning of a sentence

Guitar, ukulele, banjo—I want to learn how to play all of them!

Indicating an interruption or change in thought (informal writing)

My order was for a BLT—not a turkey club sandwich.
He’s running to the corner with—what is he doing now?

Indicating interrupted dialogue

Dorothy rambled on. “I just don’t understand why—”
“Please stop!” exclaimed Jen, exasperated.
“He should be here any—”
“Oh good,” Luke said, interrupting, “he just arrived.”

I’ve tried to be as comprehensive as possible. If you’re ever unsure whether a word or phrase should be hyphenated, check a dictionary or grammar book. If you feel this post is missing any important hyphen/dash rules or examples, please let me know in the comments.