Single vs Double Quotes
A national style difference — double in American English, single in much of British English.
American English uses double quotation marks ("...") for primary quotation and single marks ('...') for a quote inside a quote. British English traditionally inverts this — single outside, double inside — though many British publishers (notably newspapers) now use the American convention.
Neither system is more correct; both are internally consistent. The choice is a matter of house style. Whatever you pick, apply it everywhere in the same document, including titles, scare quotes, and nested quotations.
Programming and software documentation often use single quotes for strings and double quotes for output, which has nothing to do with prose style but can cause confusion in technical writing.
“British: 'She said, "Hello."' — American: "She said, 'Hello.'"”
Keep reading the glossary
The punctuation that signals direct speech or a quoted phrase — single or double, depending on locale.
A short quotation embedded directly in a sentence, inside quotation marks.
Square brackets mark editorial changes inside a quotation — clarifications, edits, or [sic].
Three dots that mark words omitted from a quotation.