Whether you use a double space after a period because it’s how you were taught or because you think it looks aesthetically pleasing, it’s time to stop. In fact, many style guides require it.
What is the Standard Double Space Rule?
Don’t do it. Only use one space after a period (or other punctuation).
The Chicago Manual of Style, the AP Stylebook, and the US Government Printing Office Style Manual all require a single space after a period. They aren’t the only ones. But it isn’t just the style guides we religiously follow that recommend only using one space. Typesetters across the board recommend one space, and often they’ll change it to one space if you didn’t. Additionally, copyeditors and proofreaders will also change your spacing to match the single space rule. (If they don’t, they should.)
Why Only One Space?
Most double space lore comes down to typewriters. Typewriters used monospaced fonts, which are fonts that have the same amount of spacing for each letter. See Courier. The i took as much space as an m or w. This made for gappy spacing between letters, but it was also the norm and people were used to it. However, as all the spacing looked the same, two spaces after a period was necessary for readability. Without the two spaces, there wasn’t a natural pause between sentences.
Today, most fonts are proportional fonts. These are fonts where the letter spacing is proportional to the width of a letter. I is narrower than m or w, so i receives less spacing. When spacing became proportional, there was no need to continue using double spaces to signify the end of a sentence in addition to the period.
What Happened Before Typewriters?
However, there is more to the traditional lore that we all believe. Spacing and typesetting was a thing before typewriters. Typesetters in pre-typewriter history used a variety of differently sized spacing between sentences–sometimes in one document. James Felici at CreativePro suggests that different spacing could have been a “boon to quickly setting justified type.” He also provides numerous examples of old documents and their spacings, so I would suggest checking out his article. He shows several different spacing trends over the decades (and longer).
Spacing is a Trend
Double or single spacing is attributed to early typesetting, not just typewriters. Spacing rules are a trend. It’s always best to follow typesetting trends, rules, and requirements of the present day as fonts are designed to follow these trends. Not following the trends, e.i., not following the single space rule, will make your document or manuscript stick out because the type looks wrong.
For example, Lawprofblawg at AbovetheLaw, wrote an opinion piece defending still using the double space. Throughout the piece, he uses different spacing lengths between sentences in different paragraphs. Some readers may not notice it or care. However, editors, typographers, typesetters, designers, or experienced readers may notice the spacing issues. The changes could pull them out of the text. It could interrupt their reading experience. This is part of the author’s point, but it also shows that our eyes become accustomed to the present day typesetting trends, even if they are simply trends.
What If I Love Double Spacing?
Unless your document or manuscript is being used in a setting where the style guide requires single spacing after a period, you could argue that you don’t need to use single spacing. See AbovetheLaw. If anything besides double spacing looks wrong, then use it. But make sure that you use it consistently. No switching on accident. Spacing must be consistent.
However, be aware your editor(s) will change it. Your publisher will change it. Someone might complain about it if it wasn’t changed. You will be going against the trends and style design expectations. Single spacing after a period is expected in current day writing. Everything else stands out.
The APA Double Space Exception
Against the common consensus of most main style guides,APA suggests using two spaces after a period in the 6th edition, much to the dismay of many writers. Their reasoning is that it helps readers of draft manuscripts. So if you’re submitting to an APA journal or a publisher that uses APA, use two spaces at the end of each sentence.
How Can I Fix Sentence Spacing?
Word processors make editing sentence spacing easy. Using the Navigation tool (Ctrl+F) with the input “. ” (period single space) and “. ” (period double space) will help you find instances of single and double spacings after a period. You can substitute other punctuation for the period if you are looking for other cases of spacing. You can also use Find and Replace (Ctrl+H) to change mass instances of double spacing to single spacing at once.
Depending on your word processor and its version, you should have a backward P button in your menu.
It’s a show/hide button or a show markup button, depending on who you ask. In MS Word, it looks like this when you hover over it:
When you have selected the show/hide button, you’ll see the formatting markings in your text. Small dots between punctuation and words indicate spacing. One dot per space.
Using this setting will show you how many spaces you typically use after each sentence or punctuation mark. However, it is much faster to Navigation (Ctrl+F) or Find and Replace (Ctrl+H) to correct spacing errors than to physically look at each sentence and count the dots between them.
As you decide to cut the double space after a period habit or argue its merits, remember the trends, proportional font spacings, and style guide recommendations. And if you keep the double spaces, be prepared to fight it out with your editor and grammar police commenters.