Hyphens and dashes

Hyphens Jump to heading

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

1. 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 your word processor’s hyphenation feature.
2. 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).
3. A hyphen is used in phrasal adjectives (commercial-speech restriction, estate-planning attorney, law-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 Jump to heading

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 dash Jump to heading

The en dash has two uses.

1. It indicates a range of values (1880–1912, 116 Cal. App. 4th 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).
2. It denotes a connection or contrast between pairs of words (conservative–liberal split, Arizona–Nevada reciprocity, Sarbanes–Oxley Act).

Em dash Jump to heading

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.