It’s a question I get asked almost every time I teach technical writing–what’s right, one or two spaces between sentences?
Strictly speaking, it’s a style issue and not a grammar issue. Style issues, and style guides, are developed by editors, grammarians and writers to answer questions not defined by grammar rules. These style guides or style sheets cover formatting, capitalization, comma placement in a series, and hundreds of other issues. Style guides need to be followed by everyone in a company to create unified, coherent, consistent documents and emails.
The most popular ones are Associated Press (AP), Chicago Manual of Style, American Psychiatric Association (APA) and Modern Language Association (MLA). Most businesses create their own style sheet, often by picking and choosing from among the most popular guides.
Back to one space or two. Newspapers have used one space for decades. So has Microsoft Word, which pulls away the second space between sentences. If you send text message, you tap the space bar twice and the first tap puts a period at the end of your sentence, and the second tap creates one space between sentences.
The single space is by far more commonly used than two spaces. We really don’t need the second space anymore. I know, I know, you learned the two-space rule and can’t possible change. I’m not going to argue with you, although I’ll tell you that I write for different clients, and shift from one to the other without too much heartburn. It takes practice, or a determination to search and replace all single spaces with doubles, for those clients who want them.
Why did we once use two spaces and why did almost all businesses decide to drop it? In the days of manual (and some electric typewriters), each letter was printed by one typewriter key. Each letter got the same amount of space, so a capital M got as much space as a lower case i. This is called monospacing–there is just one-size space for each letter.
Newspapers set their own type by placing one letter at a time into rows which were inked and pressed into the paper. The spacing between letters were controlled by typesetters–people who put the letters into place. They could push the letters that needed fewer space–i, l, f, t in lowercase, for example–closer together and leave a bit more space for capitals that needed more space: M, N, Z, W, and X.
This kind of spacing, which takes into account the width of each letter, is called proportional spacing. You can see an example of both kinds of spacing on the left.
The art of knowing how much space to use between letters for making the font easy to read is called kerning. It makes reading faster and easier and it allows people to understand more of the words in print.
Back to the squabble for one space or two–we really don’t need the second space anymore. Most fonts are now
proportionally spaced. The second space has two disadvantages. First, it creates a gap between sentences, making the eye work a bit harder. When most people have to work a bit harder, they don’t. They skim or skip or stop reading.
The second reason is one you probably have experienced. Cut and paste a Word document into another software, and you disturb the order of the coding in Word. You may get odd paragraph or page spacing, or be unable to close a large space between paragraphs.
I will agree that the time spent at a newspaper got me used to using and preferring one space, but we’ve had proportional type fonts at our fingerprints for more than three decades now, and I think it’s time to go with the kerning flow.
—Quinn McDonald has a deep love of fonts, which she still calls typefaces.