Quotations

In English writing, quotation marks or inverted commas (informally referred to as quotes or speech marks) are punctuation marks surrounding a quotation, direct speech, or a literal title or name. Quotation marks can also be used to indicate a different meaning of a word or phrase than the one typically associated with it and are often used to express irony. Quotation marks are sometimes used to provide emphasis, although this is usually considered incorrect.
Quotation marks are written as a pair of opening and closing marks in either of two styles: single (‘…’) or double (“…”). Opening and closing quotation marks may be identical in form (called neutral, vertical, straight, typewriter or "dumb" quotation marks), or may be distinctly left-handed and right-handed (typographic or, colloquially, curly quotation marks); see quotation mark glyphs for details. Typographic quotation marks are usually used in manuscript and typeset text. Because typewriter and computer keyboards lack keys to directly enter typographic quotation marks, much typed writing has neutral quotation marks. The “smart quotes” feature in some computer software can convert neutral quotation marks to typographic ones, but sometimes imperfectly.
The closing single quotation mark is identical or similar in form to the apostrophe and similar to the prime symbol. However, these three characters have quite different purposes. The double quotation mark is similar to, and often used to represent, the ditto mark.
Usage:
Single or double quotation marks denote either speech or a quotation. Double quotes are preferred in the United States, and also tend to be preferred in Canada, Australia and New Zealand. Single quotes are more usual in the United Kingdom and South Africa, though double quotes are also common there. A publisher's or author's style may take precedence over regional general preferences. The important idea is that the style of opening and closing quotation marks must be matched:
'Good morning, Frank,' said Hal.
"Good morning, Frank," said Hal.
For speech within speech, the other style is used as inner quotation marks:
'Hal said, "Good morning, Dave,"' recalled Frank.
"Hal said, 'Good morning, Dave,'" recalled Frank.
Sometimes quotations are nested in more levels than inner and outer quotation. Nesting levels up to five can be found in the Christian Bible. In these cases, questions arise about the form (and names) of the quotation marks to be used. The most common way is to simply alternate between the two forms, thus:
"...'..."...' ... '..."...'..."