The Editor’s Manual
Free learning resource on English grammar, punctuation, usage, and 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.
Use square brackets within parentheses to show brackets within brackets. In British style, round brackets are used within round brackets. Avoid using nested parentheses in U.S. writing.
Use “which” to introduce a description. As a relative pronoun, “which” connects a relative clause to the noun it describes. Differences exist between American and British usage.
“That” introduces information that is essential to meaning and not enclosed in commas. “Which” introduces additional, optional details enclosed in commas. In British usage, it also introduces essential information.
Use commas before and after the year in the American date format (May 1, 2021) but not in British (1 May 2021). No comma is needed when only the month and year are specified (May 2021).
American date format is month-day-year (May 1, 2021); British is day-month-year (1 May 2021). Use commas between day and year in American English; no commas are needed in dates in British English.
To show the exact date, spell out the month, and write the day and year in numerals (May 1, 2021, or 1 May 2021). Don’t place a comma between month and year (May 2021). Spell out the day when it stands alone.
The serial comma is used before the conjunction (“and,” “or”) that marks the final item in a series. Using it is optional, but it can sometimes affect the meaning of a sentence.