Single or double?
Which is correct: a single or a double space between sentences?
Shutterstock / Africa Studio / An old-fashioned typewriter and a modern laptop facing each other on a tabletop
I’m old enough to remember using a typewriter. I used one for a few years, but in the early nineties computers became cheaper and more commonplace. I then stopped using the ‘old’ technology of typewriters and started word processing with a computer.
Looking at how many people around the world are old enough to remember typing papers with a typewriter, and the inevitable stuck keys, whiteout and carbon copy paper, I found that the world’s median population age is estimated to be 30.4 years. This means half the world’s population is older than 30.4 and half is younger. It also means that half the world’s population arose after computers became commonplace.
You may recall the historical reasoning for using double spaces between sentences. Typewriters generally used one font, Courier. And the Courier font is monospace, meaning it is of a fixed width, so all letters and spaces occupy the same horizontal space.
Most fonts used today are variable-width fonts, meaning that letters and spaces all have variable widths. If you open up a document in Word and change the font to Courier, you will see the difference. You may also observe how difficult it is to discern the white space between sentences in Courier … unless you use two spaces between sentences.
Now that word-processing software relies on variable-width fonts this spacing is less of an issue. However, that’s not the end of the story.
There are numerous studies that attempt to explain whether it is easier or more difficult to read text with single or double spaces between sentences. You can research the issue online and find plenty of papers to support your view, no matter which side of the argument you are on.
If we look to published style manuals for guidance, we see that most dictate a single space between sentences, including The Chicago Manual of Style and the 6th edition of the Australian Style Manual. Even the Publication Manual of the American Psychological Association now recommends a single space in their new edition (7th edition).
In the end, it may just come down to personal choice.
“What is important, from an editorial perspective, is that those spaces (whether single or double) are used consistently throughout your document.”
This is one of the checks I do when I start editing a new paper, and depending on the length of the paper and how inconsistent the author has been, it can take a noticeable amount of time to correct.
So, from an author’s perspective, it is best to define from the outset whether you prefer single or double spaces between sentences, and to stick to that. Ensure your editor is informed of your style choice.
However, be warned: if the paper is to be typeset by a publisher, you will likely lose all of those double spaces as they convert the text to the publisher’s house style. And you will definitely lose those double spaces when your text is converted into HTML code for online publication because double spaces drop out when converted to code.
Regardless, rest assured that if you choose to use double spaces, it will look strange for at least half the world’s population, or those under the age of 30.4, and if you use single spaces it likely will look strange for the other half of the world’s population. So either way, you have a 50:50 chance of getting it ‘right’.
