Parentheses Usage
Parentheses signal that enclosed material is secondary to the main sentence. Keep them sparse, distinguish them from square brackets, and place surrounding punctuation according to whether the parenthetical is part of another sentence or is a complete standalone sentence.
Use parentheses to enclose supplementary information, clarification, abbreviations, citations, or asides that are less central than the surrounding sentence. The sentence should normally remain grammatically workable when the parenthetical material is removed.
Key details
Important caveats
Boundary
Avoid nested parentheses where possible. If an insertion inside parentheses is unavoidable, the governing style may call for square brackets.
Further guidance
Decision Path
Ask whether the information is useful but nonessential to the core grammatical structure. If it is central, integrate it directly instead of hiding it in parentheses.
Punctuation
When a parenthetical sits inside a sentence, the sentence’s terminal punctuation normally remains outside. A complete independent parenthetical sentence can carry its own punctuation.
Worked Example
“The committee met on Tuesday (the only day all members were available).” The parenthetical adds useful detail, but the main sentence remains complete without it.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Brackets and parentheses (opens in a new tab)Australian Government Style Manual · Explains parentheses for extra detail, clarifications, asides and citations and gives punctuation rules for content inside and around parentheses.
- Punctuation Exercise (opens in a new tab)Purdue Online Writing Lab · Provides context-sensitive practice involving parentheses alongside other punctuation, supporting a usage guide that distinguishes parenthetical functions from surrounding sentence punctuation.