The overwhelming majority of contemporary style guides and word processors advise using a single space between typed sentences. When in doubt, use single spacing in research papers, essays, and your creative writing. This is true regardless of whether your sentence ends in a period, a question mark, or some other form of punctuation. Single spaces should also follow commas, as well as periods after abbreviations.
How Many Spaces Should You Use After a Period?
In addition, the style guides below recommend single spaces, rather than double spaces, between sentences. Where possible, I have linked to the direct guidance from the appropriate style guide.
- Associated Press Stylebook by the Associated Press
- MLA Handbook by the Modern Language Association
- The Chicago Manual of Style by the University of Chicago
- APA Style by the American Psychological Association [Guidance]
- The Microsoft Manual of Style for Technical Publications by Microsoft
- The Gregg Reference Manual by William A. Sabin