Here is a client question received today, which I often hear in business writing courses:
I was taught that two spaces should follow a period in a paragraph. I was working on a document and noticed the author used both one space and two spaces between sentences. I changed all of the occurrences to two spaces, but in discussions with others, I was told a single space is now the new norm.
Which one is correct? One or two spaces?
I have a clear answer for this question: One space is correct.
Two spaces is a holdover from the days of typewriters, when two spaces were required after any full stop (period, question mark, or exclamation mark.) Word processors take care of spacing automatically.
My three most valued business writing style guides support one space: The AP Style Guide, Gregg Reference Manual, and Chicago Manual of Style. The academic style guide APA (American Psychological Association) also recommends one space. Interestingly, MLA (Modern Language Association) recommends and uses one space but states two spaces is also acceptable.
I disagree with MLA on this. Using two spaces looks old-fashioned.
To ensure your writing is correct, use one space after a full stop or colon. One space is visually more crisp and it shows your business writing format is current.
Old habits can be difficult to break, of course, but with focus one space will become your natural impulse. If you find it hard to use one space after many years of adding two spaces after a full stop or colon, just use the "find and replace" option in your word processor to remove the extra space after every sentence in a document.