Dash (punctuation)

Forms and characteristics

Two principal dashes are commonly described: the em dash (—), about the width of a capital M, and the en dash (–), about the width of a capital N. A shorter figure dash exists in typesetting, and the hyphen (-) is separate in use and size. The em dash often marks interruptions or strong parenthetical statements; the en dash commonly denotes ranges (e.g., 1998–2005) or connections (e.g., New York–London flight).

Common uses and examples

• Interruption or abrupt change: "She opened the door—and froze."
• Parenthetical thought with strong emphasis: "The results—surprisingly consistent—changed the theory."
• Ranges or spans: "pages 10–15" or "June–August."
• Compound relationships: "the Nobel Prize–winning scientist."

Writers choose between en and em dashes based on meaning: use an en dash for ranges and links, and an em dash for breaks in sentence flow or dramatic emphasis. The hyphen remains the connector for compound words (well-known) and for splitting words at line breaks.

Style and regional differences

Spacing conventions vary. American style usually places em dashes without spaces: "word—word." Some British and other styles prefer spaced dashes: "word — word." Publishers and style guides differ about whether to use em dashes for parenthetical phrases or to prefer commas or parentheses instead.

History and practical notes

The names em and en derive from the approximate widths of the letters M and N in traditional typesetting. Today, dashes are produced by keyboard shortcuts, automatic substitutions in word processors, or by inserting the appropriate Unicode character. Screen readers and accessibility tools may read dashes as a pause; clear usage helps comprehension.

For further reading on punctuation and related marks, see entries on dash and hyphen.