].5 Uses, 2 Misuses
An em-dash (—) is a horizontal line that marks an emphatic insertion, an informal introduction, or a sharp break in thought. It is not so called because it runs the width of a capital M (a common misconception). Rather, it takes its name from a unit of typographic measurement: an em was the height of a traditional metal piece of type (about the width of a capital H). Copyeditors signal it by the mark [].
496 Use a pair of em-dashes to set off an inserted phrase that, because of what it modifies, needs to go in the middle of a sentence.
• I think you behave—and write—nicely, nobly even, if you like to be told so. (Algernon Charles Swinburne)
• In America—as elsewhere—free speech is confined to the dead. (Mark Twain)
• A curious machinery of effort is the best—even the simplest—imitation of the laws of nature. (Garry Wills)
• It is doubtful that public support will be forthcoming unless the libraries—public and university both—do a better job of presenting their case to the public than has been done until now. (Norman Cousins)
497 Use an em-dash to set off a parenthetical phrase that you want to highlight.
• He was not exactly a mathematician, but he had the true architect’s love for the perfect figures of solid geometry—the cube, the sphere, the cylinder, the cone—and the things that happen when these figures intersect each other. (John Summerson in reference to Sir Edward Lutyens)
• We have lately been making difficulties about passports—not merely keeping foreigners out but even forbidding our own citizens to travel in foreign countries—very much in the Russian fashion. (Edmund Wilson)
• They say—the astrologers, I mean—that it will get better and better for me as I go on. (Henry Miller)
• I suppose we all—even nuns—dream of a life other than the one we actually live on this indifferent earth. (Larry McMurtry)
498 Use an em-dash to tack on an important afterthought.
• Livia was in the Box, too—a peculiar honor paid her as my father’s mother. (Robert Graves)
• He just liked the early morning to himself, quiet, no voices—especially not Marion’s voice. (Raymond Chandler)
• They might call him a watchman but he was a pimp—a dirty pimp, the lowest thing in the world. (John Steinbeck)
• It was June when we buried him—the summer solstice. (Susan Cheever)
499 Use an em-dash to introduce a specification or a list when more of a pause is suggested than a colon might convey.
• They sold everything here—fruit, vegetables, dairy, geese, fish. (Isaac Bashevis Singer)
• The great Russian writers are like men deprived by an earthquake or a railway accident not only of their clothes, but also of something subtler and more important—their manners, the idiosyncrasies of their characters. (Virginia Woolf)
• This rule fulfills three purposes—it expresses snobbish feeling, it measures competitive power, and it passes on to the degree-granting institution the task of judging intellectual and scholarly aptitudes. (Jacques Barzun)
500 Use an em-dash to show hesitation, faltering, or interruption.
• “I—I—don’t know, sir,” replied Oliver. (Charles Dickens)
• “Ralph, wow, I—I feel better already.” (Thomas Pynchon)
• “You are just what I—what I wanted,” he said. (Frances Hodgson Burnett)
• The thing that made Will laugh most was that the very fellow who did it got his trousers burnt trying to put out the fire, and he asked the—is it Faculty or President? (Louisa May Alcott)
• “After that”—his voice faltered—“that—machine, for duplicating the glass. Well, the machine did its work.” (William F. Buckley)
• CARROLL. Come, come! But she—?
STEPHEN. She was fine. She insisted that we should fight it together. (J. M. Barrie)
• “No tricks now or—.” “Oh, you can trust me, you can trust me!” (Sir Arthur Conan Doyle)
501 Don’t use more than two em-dashes in a sentence.
Not this: The circumstances of this death are completely distorted by the professor, a fateful follower of the gentlemen of the daily press who—perhaps for political reasons—had falsified the culprit’s motives and intentions without awaiting his trial—which unfortunately was not to take place in this world.
But this: The circumstances of this death are completely distorted by the professor, a fateful follower of the gentlemen of the daily press who—perhaps for political reasons—had falsified the culprit’s motives and intentions without awaiting his trial, which unfortunately was not to take place in this world.
Not this: It had added some editorial pages that dealt only with local problems—the hideous new lamp standards, infrequent buses on the Number 11 route, the theft of milk bottles—things that really interested only one group of people—housewives.
But this: It had added some editorial pages that dealt only with local problems—the hideous new lamp standards, infrequent buses on the Number 11 route, the theft of milk bottles—things that really interested only one group of people: housewives.
It’s not wise to violate the rules until you know how to observe them.
—T. S. Eliot
quoted in Good Advice on Writing, William Safire and Leonard Safir, eds.
502 Don’t use a comma, colon, semicolon, or terminal period before an emdash. A question mark or exclamation point is acceptable in that position.
Not this: They were waiting for her outside the warehouse;—Bill, hands in pockets, was leaning against the railing and watching as the hoodlums stalked around their smashed bikes, cursing and swearing.
But this: They were waiting for her outside the warehouse; Bill, hands in pockets, was leaning against the railing and watching as the hoodlums stalked around their smashed bikes, cursing and swearing.
Not this: She remembered the girl in the coffee shop who had been staring at David. There was something about her face:—girls always gave that certain move when they thought someone was cute.
But this: She remembered the girl in the coffee shop who had been staring at David. There was something about her face—girls always gave that certain move when they thought someone was cute.
Not this: Herbert flinched.—Violet turned away from him and walked back toward the shimmering curtain of air that he had come through.
But this: Herbert flinched. Violet turned away from him and walked back toward the shimmering curtain of air that he had come through.