Writing tip: How many spaces after a period?

Theresa Bell

If an author is following the style rules of the American Psychological Assocation (APA), how many spaces should he or she include after the closing period in a sentence? You might think this query would have a simple and noncontroversial answer since the APA (2010) noted that authors should, "space twice after punctuation marks at the end of a sentence" (p. 88). There isn't any ambiguity there, so where's the controversy? The problem is that most style guides, such as the Chicago Manual of StyleAP stylebook, and the MLA style manual require the widely-accepted approach of one space after a closing period (Fogarty, 2009, para. 1). The Canadian Press (2008) also recommended one space (p. 384), as did the APA (2001) in the fifth edition of their style manual (p. 290). Nevertheless, in the sixth edition of the manual, the APA (2010) recommended two spaces after closing punctuation (p. 88), and as Wiederkehr (2009) explained in the APA Style Blog, the rationale for the change was improved readability (para. 3). A debate raged in the blog's comments regarding the validity of the rationale, and while there was an acknowledgement by an APA expert that different audiences (e.g., publishers) might have differing expectations (Lee, 2009, para. 2), the APA experts stuck to their two-space rule when responding to comments.

Interestingly, however, on March 18th, 2014, @APA_Style, which is the official twitter account for the Publication Manual of the American Psychological Association (6th ed.), tweeted the following:


The tweet reflects what I’ve heard from most RRU instructors on the topic, which is that they aren’t particularly concerned whether students use one or two spaces as long as the spacing is consistent. Accordingly, unless an editor or instructor has directed you specifically to use one or two spaces after closing punctuation, please use the approach that works best for you and be consistent. There are so many things for authors to concern themselves with when they’re writing; thanks to this tweet from the APA, a debate over spacing after periods doesn’t need to be one of them.

Theresa Bell
Writing Centre Coordinator


American Psychological Association. (2001). Publication manual of the American Psychological Association (5th ed.). Washington, DC: Author.

American Psychological Association. (2010). Publication manual of the American Psychological Association (6th ed.). Washington, DC: Author.

American Psychological Association [APA_Style]. (2014, March 18). @FMCatalano @craigbeebe @StacyLOliver APA allows either 1 or 2 spaces after a period; just be consistent. Everybody's happy [Tweet]. Retrieved from https://twitter.com/APA_Style/status/446010271002558464

Canadian Press. (2008). The Canadian Press stylebook: A guide for writers and editors (15th ed.). Toronto, Canada: Author.

Fogarty, M. (2009, July 31). How many spaces after a period? It depends [Blog post]. Retrieved from http://www.quickanddirtytips.com/education/grammar/how-many-spaces-after-a-period?page=1

Lee, C. (2009, August 3). On two spaces following a period [Blog post comment]. Retrieved from http://blog.apastyle.org/apastyle/2009/07/on-two-spaces-following-a-period.html#comment-6a01157041f4e3970b011571621418970c

Wiederkehr, S. (2009, July 30). On two spaces following a period [Blog post]. Retrieved from http://blog.apastyle.org/apastyle/2009/07/on-two-spaces-following-a-period.html