Dictionary of English - quotation marks

Whether the direct speech comes first, last, or is broken, the inverted commas must enclose only the words that the speaker actually utters. The punctuation marks are part of the speech; they must be inside the inverted commas: 'You said, 'Go home!' Those were your very words. No wonder he's upset,' said Steven angrily. 'I said 'Go home if you want.' He didn't have to go,' replied John. Here the reported speech within the dialogue and the dialogue itself can be distinguished by the use of single and double quotation marks.

Quotation marks are sometimes used to indicate the title of a play, a book, the name of a ship, and so on, but italics (or underlining) are normally used for these, and both may be omitted. Quotation marks may also be used to indicate that the writer is using the word in an unusual, often ironic, way: He is one of these 'modern' young men – appalling manners and terrifying appearance. In British English, single quotes are now more commonly used than double ones, and double quotes within single; in American English normal practice is the other way round.