hyphens and dashes Use them, don’t confuse them

Hy­phens and dashes look sim­i­lar, but they’re not interchangeable.

Windows Mac OS HTML - hyphen - - - – en dash alt 0150 option + hyphen – — em dash alt 0151 option + shift + hyphen —

The hy­phen ( - ) is the small­est of these marks. It has three uses.

A hy­phen ap­pears at the end of a line when a word breaks onto the next line. These hy­phens are added and re­moved au­to­mat­i­cally by the au­to­matic hy­phen­ation in your word proces­sor or web browser. Some mul­ti­part words are spelled with a hy­phen (topsy-turvy, cost-ef­fec­tive, bric-a-brac) . But a pre­fix is not typ­i­cally fol­lowed with a hy­phen (nonprofit , not non-profit) . No hy­phen is nec­es­sary in phrasal ad­jec­tives that be­gin with an ad­verb end­ing in ‑ly (it’s a closely held com­pany , not a closely-held com­pany ). Nor is a hy­phen nec­es­sary in mul­ti­part for­eign terms or proper names used as ad­jec­tives ( habeas cor­pus ap­peal on the Third Cir­cuit docket , not habeas-cor­pus ap­peal on the Third-Cir­cuit docket ). A hy­phen is used in phrasal ad­jec­tives (lis­tener-sup­ported ra­dio, dog-and-pony show, high-school grades) to en­sure clar­ity. Non­pro­fes­sional writ­ers of­ten omit these hy­phens. As a pro­fes­sional writer, you should not. For in­stance, con­sider the un­hy­phen­ated phrase five dol­lar bills . Is five the quan­tity of dol­lar bills , or are the bills each worth five dol­lars ? As writ­ten, it sug­gests the for­mer. If you mean the lat­ter, then you’d write five-dol­lar bills .

Dashes come in two sizes—the en dash and the em dash . The em dash ( — ) is typ­i­cally about as wide as a cap­i­tal H. The en dash ( – ) is about half as wide.

En and em dashes are of­ten ap­prox­i­mated by typ­ing two or three hy­phens in a row ( -- or --- ). Don’t do that—it’s an­other type­writer habit. Use real dashes.

The en dash has two uses.

It in­di­cates a range of val­ues (1880–1912, pages 330–39, Ex­hibits A–E) . If you open with from , pair it with to in­stead of an en dash (from 1880 to 1912 , not from 1880–1912) . It de­notes a con­nec­tion or con­trast be­tween pairs of words ( con­ser­v­a­tive–lib­eral split , Ari­zona–Nevada re­ci­pro­city , Sar­banes–Ox­ley Act ).

The em dash is used to make a break be­tween parts of a sen­tence. Use it when a comma is too weak, but a colon, semi­colon, or pair of paren­the­ses is too strong. The em dash puts a nice pause in the text—and it is un­der­used in pro­fes­sional writing.