How To Use The Em Dash

Few punctuation marks are as divisive as the em dash. Used in place of commas, parentheses, or colons, the em dash () sets off a word or clause with added emphasis. It’s the longest of the dashes, and it signals a disruption in the sentence’s flow. For example, F. Scott Fitzgerald uses one in The Great Gatsby to show an interruption in train of thought: “Only Gatsby, the man who gives his name to this book, was exempt from my reactionGatsby, who represented everything for which I have an unaffected scorn.”

Joining Independent Clauses

The em dash can join two independent clauses in place of a semicolon, lending a more casual tone. Mark Twain provides an example in The Adventures of Huckleberry Finn: “Well, nobody could think of anything to doeverybody was stumped, and set still.”

It can also replace a colon to introduce phrases, clauses, or examples. This can either soften formality or add color, as in this example from The Tragedy of Pudd’nhead Wilson: “Each person is born to one possession which outvalues all his othershis last breath.”

Substituting for Unknowns

The em dash has another job. It can substitute for an unknown element, like a missing word or letter. Typically, two em dashes represent the absence of one or more letters in a word. Three em dashes indicate the absence of an entire word. This format is often used in bibliographies when citing multiple works by the same author. It can also show a lack of clarity in transcripts.

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Stylistic Choices

A lot of writers have notably adapted the em dash to suit their own purposes. James Joyce uses the em dash rather than quotation marks throughout Ulysses. Emily Dickinson uses dashes rather than commas in most of her poetry. These uses are mainly personal style choices.

There’s some disagreement among grammar experts as to when and how to use the em dash. Some believe it’s overused among contemporary writers. Others dislike the way it disrupts sentences. William Strunk Jr. and E. B. White argue for moderation. In The Elements of Style they recommend that writers “use a dash only when a more common mark of punctuation seems inadequate.” They also say, “A dash is a mark of separation stronger than a comma, less formal than a colon, and more relaxed than parentheses.”

Formatting an Em-Dash

An em dash is approximately the same length as the letter M, making it longer than both the hyphen () and the en dash (). Different style guides have different rules whether to use em dashes and how to format them. Most newspapers (which follow The Associated Press Stylebook) add a space on either side of it. Many other style guides opt not to add the spaces. Some editors use two hyphens to replace the em dash. If you’re not using a style guide, the most important thing is to be consistent throughout your work.

Typing an Em Dash

Typing an em dash is a little different depending which operating system you’re using. In most word processing programs (like Microsoft Word or Google Docs), you can find it listed under Special Characters or Symbols. Most of these programs (as well as some email clients) will even autocorrect if you type . You may be using em dashes without even realizing it!

In Microsoft Word, you can type an em dash by pressing Ctrl, Alt, and the on your number pad. On a PC, you can type an em dash anywhere by pressing Alt and 0151 on the number pad. On a Mac, you can press Option, Shift, and .