The Editor's Manual
Free learning resource on English grammar, punctuation, usage, and style.
Commas and periods always go inside quotes in American style. In British style, they go inside only if they apply to the quoted text. In all styles, question marks and exclamation points go inside only if they apply to the quoted text.
Periods always go inside quotation marks in American usage. In British usage, a period (or full stop) goes inside only if the quotation is a complete sentence.
Commas always go inside quotation marks in American style. In British style, commas go inside or outside depending on whether they punctuate the text within quotes or the surrounding sentence.
Use single inside double quotation marks to show a quote within a quote in US style. In British style, use double inside single quotes.
Double quotes generally enclose text in US style; single quotes, in British. Single quotes are used only for quotes within quotes in US style; double quotes, in British. Commas and periods always go inside quotation marks in US style but not in British.
Double quotes enclose text in US style, with single quotes used only for quotes within quotes. Single quotes are the default in British and Australian style, with double quotes reserved for quotes within quotes.
Use either a comma or a colon after a greeting. The colon is preferred in business or other formal communication in U.S. style.
Place quotation marks around direct speech or a quotation. Quotes may also enclose a word or a phrase used ironically or as itself. Quotation marks set off titles of shorter works (like a chapter, article, or poem).
Round brackets are called “parentheses” in American English but referred to simply as “brackets” in British English. In American writing, square brackets are used within parentheses, while the British use round within round brackets (nested parentheses).
Parentheses set off information that may be useful but is tangential to the primary meaning of the passage. Square brackets enclose editorial clarifications to quoted text. Square brackets are also used as brackets within brackets.