What’s the difference between a hyphen, an en dash, and an em dash? Well, how long have you got? Literally. Hyphens (-) are the shortest. En dashes (–) are in the medium range, and em dashes (—) are the longest. Length aside, the types of dashes perform different duties, and they are not interchangeable. This guide will help you better understand these three short, but distinct, grammatical lines.
Hyphen
This tiny punctuation mark joins related words into a single word. Hyphens are often used to form compound words, join adjectives, express numbers or ages, and simplify prefixes. Here are some examples:
part-time
off-campus
good-hearted
chocolate-covered
three-quarters
seven-year-old
mid-September
ex-wife
twenty-one
(Note: Sometimes a style guide will call for spelling out only numbers less than 10, but in personal writing, consistency rules. Even in AP style, numbers greater than nine are spelled out at the beginning of a sentence.)
Hyphens highlight the relationship between two words. The rules of hyphenation can be complex, but the main thing to remember is that hyphens generally link words to create new meanings. Some exceptions include hyphenating letters to show they are being spelled out (“c-a-t”) or to indicate specific sounds (“It’s c-c-c-cold outside”).
En Dash
Editor’s note: AP style, which Word Genius follows, does not use en dashes. The following is based on accepted punctuation rules.
This mid-size dash gets its name from typesetting tradition, because it’s supposed to be the same width as a letter “N.” It typically shows the relationship between words, dates, or numbers. Generally, it’s used to indicate a range. For example:
The classes read pages 50 – 60 for homework.
She worked at the bank January – May.
It’s important to note that the en dash replaces words such as “from” or “between” before the noted range. In other words, “She worked at the bank from January – May” is incorrect. The use of the en dash in the range eliminates the need for the preposition.
An en dash can also be used to record results:
The vote was 5–2 in favor of the proposal.
The Red Sox beat the Yankees 10–9.
(Note: With scores and results, there are generally no spaces on either side of the en dash.)
It can also be used in place of the word “versus.”
Tonight is the Miami–Dallas game.
We’re reading about the Lincoln–Douglas debate.
Some writers also use the en dash instead of a hyphen in certain compound words, but this is more of an aesthetic choice. If treating the en dash as a stylistic effect, it’s important to remain consistent throughout the piece.
Em Dash
The longest of the dashes, the em dash gets its name because it’s roughly the width of the typed letter “M.” Whereas the other two dashes function mostly within words or terms, the em dash is mainly used as a part of the sentence as a whole. It can fill in for a comma, colon, semicolon, or parenthesis.
Adding em dashes is often a matter of taste. Is it possible to overuse em dashes? Of course — as with any stylistic punctuation mark, they should be used with purpose and intention.
Em dashes are ideal for adding drama to a sentence:
The line was long — stretching to the very back of the department store.
They can draw attention to a phrase or idea:
Our teacher — an award-winning novelist — showed us how to structure a story.
Em dashes can replace parentheses:
The doctor — who was wearing a white lab coat and stethescope — listened to my heart.
A writer might use one in dialogue to show that speech has been suddenly cut off:
“I forgot to mention — ” Damien yelled as the bus pulled away.
One final note about em dashes — they can be used both with and without spaces around them. Newspapers and magazines that follow the AP Stylebook will use spaces on either side of the em dash (“It’s the person I was looking for — Don!”). But books and professional journals, which usually follow The Chicago Manual of Style, delete the spaces on either side of the em dash (“It’s the person I was looking for—Don!”). It all comes down to which style guide you want to follow — or just personal preference.
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