Other Punctuation: Hyphens, Dashes, Parentheses & Ellipses

Introduction

Advanced punctuation shows relationships. A hyphen joins words, a dash interrupts or emphasizes, and an ellipsis marks omitted words or a trailing thought.

Hyphens in Compound Modifiers

Hyphenate words that work together before a noun when the hyphen prevents a misreading: a well-researched proposal, a two-hour workshop. A familiar compound after the noun is usually open: The proposal was well researched. Do not hyphenate an -ly adverb plus an adjective: a carefully revised report. Consult a current dictionary when usage is uncertain.

Worked example: In The committee approved a three year plan, three and year jointly modify plan: a three-year plan. In The plan will last three years, no hyphen is needed.

Dashes and Parentheses

An em dash (—) marks a sharp interruption, an emphatic addition, or parenthetical information. Use a pair around an internal interruption: The final chapter—unlike the first two—uses a first-person narrator. A single dash can introduce an emphatic ending: The team needed one thing—time. Parentheses make an aside less prominent. Match both marks in a pair.

Worked example: The library's newest service a tool-lending desk opens Monday becomes The library's newest service—a tool-lending desk—opens Monday.

Ellipses

An ellipsis usually shows that words were omitted from quoted material. The remaining quotation must preserve the original meaning and remain grammatical. An ellipsis may also show a thought trailing off in dialogue, but it should not replace ordinary end punctuation in formal prose.

Worked example: Original: The board will review the proposal at its Thursday meeting before publishing a decision. Shortened: The board will review the proposal ... before publishing a decision.

Quick Reference

• Hyphen: joins words that act together before a noun when needed for clarity.
• Paired em dashes: enclose an emphatic interruption.
• Single em dash: introduces a forceful explanation or ending.
• Parentheses: enclose a less prominent aside.
• Ellipsis: marks omitted quoted words or, in dialogue, a trailing thought.