When not to use double quotation marks:
Do not use double quotation marks when trying to hedge (APA, 2010, p. 92), as in the next example.
Ex., The teacher rewarded the class with tokens.
In the previous example, it is not necessary to put “rewarded” in quotation marks.
The APA manual also advises not using quotation marks to introduce a key phrase or a technical phrase. It recommends the use of italics instead.
Ex., She compared it with meta-analysis, which is described in the next section (p. 91).
Disciplines may vary with regard to this last point, so always check with your department or professor to see whether your school uses quotation marks or italics. Remember, if you do decide to use quotation marks to signal key concepts, make sure they are double.
American English practice differs from that of British English. If you live in the United States and are seeking to publish in U.S. journals, it is advisable to use our system. Though nowadays there is a trend toward using single quotation marks instead of double marks, I recommend that you not jump on the bandwagon (even if CNN is doing it). The rule is simple: Use single quotation marks only to indicate a quote within a quote. Unless you are writing a paper in linguistics, philosophy, or theology, you should be using double quotation marks for all of the cases discussed in this article. Tina Blue sums it up nicely at the end of her article: “We should just stick with the conventions that are already familiar to us, so we don’t commit the crime of stylistic inconsistency, which is always a danger when you try to adopt someone else’s way of doing things.”
American Psychological Association (APA). 2010. Publication Manual of the American Psychological Association (6th ed.). Washington, DC: Author.
Bell, J. (2008). Clean, Well-Lighted Sentences: A Guide to Avoiding the Most Common Errors in Grammar and Punctuation. New York, NY: W. W. Norton.
Blue, T. (2001, January). Single vs. double quotation marks: Once again British and American usage differ.
Merriam-Webster. (1995). Merriam-Webster’s Guide to Punctuation and Style. Springfield, MA: Author.
University of Chicago Press. (2003). The Chicago Manual of Style (15th ed.). Chicago, IL: Author.