Quotation marks, also called inverted commas in British English, are used to enclose quotations in your text:
‘If I have seen further it is by standing on the shoulders of giants’, Isaac Newton.
‘Single’ or “double”?
Quotation marks can be ‘single’ or “double”. They are written in the pattern 6–9 for single and 66–99 for double quotation marks, and always above the line (not below the line as in some languages), for example:
The Anti-Apartheid Movement campaigned for ‘One man, one vote’ in South Africa.
The Civil Rights Movement campaigned for “One man, one vote” in the United States.
You can use either single or double quotation marks, though you should be consistent throughout your text and follow any guidelines for your subject, journal or publisher. Generally, British English uses single quotation marks, while US English uses double quotation marks.
‘“Quotations” within quotations’
For quotations within quotations, use double quotation marks if you normally use single quotation marks, and single quotation marks if you normally use double quotation marks. For example:
The Anti-Apartheid campaigner stated, ‘We will not rest until we achieve “One man, one vote” in South Africa’.
The Civil Rights campaigner stated, “We will not rest until we achieve ‘One man, one vote’ in the United States.”
If you are citing a very long quotation, you should normally place it in its own indented paragraph, for example:
Darwin, Voyage of the Beagle, October 1835:
‘I will not here attempt to come to any definite conclusions, as the species have not been accurately examined; but we may infer, that … the organic beings found on this archipelago are peculiar to it … This similarity in type, between distant islands and continents, while the species are distinct, has scarcely been sufficiently noticed. The circumstance would be explained according to the views of some authors, by saying that the creative power had acted according to the same law over a wide area.’
In university and research writing, beware of using quotation marks to enclose loose definitions, slang or imprecise phrasing:
The results were ‘OK’.
Columbus ‘discovered’ the ‘New’ World in 1492.
She spoke with a ‘posh’ accent.