Square Brackets vs Parentheses
Brackets mark what someone else added to a quotation; parentheses mark what the original author wrote.
Inside quoted material the distinction is strict. Square brackets enclose an editor's or quoter's insertion — a clarifying name, a changed capital, a translation. Parentheses inside a quotation belong to the person being quoted.
Getting this backwards silently rewrites the source: parentheses around your own clarification attribute your words to the speaker, which is misquotation even when the added information is correct.
Outside quotations the two are ordinary punctuation, with parentheses for asides and brackets reserved for nesting inside parentheses in some styles. The strict rule applies specifically within quoted text.
Common mistake: bracketing so much that the quotation is mostly yours. If more than a few words need insertion, paraphrase and quote only the phrase that must be exact.
“"He [the treasurer] resigned in April (or so the minutes claim)."”
Keep reading the glossary
Square brackets mark editorial changes inside a quotation — clarifications, edits, or [sic].
An editor's word or phrase inserted inside a quotation, marked with square brackets.
A signed comment by an editor, distinct from the author's own text or notes.
Latin for 'thus' — used in quotes to mark an error reproduced from the original.