Sometimes I’m surprised at how tightly some otherwise clear-thinking people cling to what they learned in high-school typing class. When I took typing in high school, 37 years ago, I was taught to hit the space bar twice after each sentence. That was a good lesson back then, because I was typing on an Underwood manual typewriter, a machine incapable of producing anything in a proportionately spaced font.
Today, if you’re reading this blog post, then you probably write on a computer, not an Underwood typewriter. And unless you’re perverse enough to have set the default font in your word-processing software to Courier, everything you write on your computer is written in a proportionately spaced font. This fact makes the two-spaces rule obsolete. Once space after each sentence is enough.
Recently John McIntyre wrote about this; the flak he caught prompted him to write two follow-up posts (here and here). Me, I’m left wondering why anyone who cares deeply about getting their writing right would be so unwilling to re-examine what they learned in high school.
My prior blog posts on this should-be-uncontroversial topic are here, here, here, and here.
(Photo credit.)

They still teach double-spacing in many high school computer classes.
Yes, I'm serious.
Sigh.
Posted by: Max Kennerly | 15 August 2010 at 05:51 PM
Who cares? I'll always do two spaces, and I LEARNED to type on a computer. It's common practice, and look, my words are on the screen with two spaces, and the world isn't ending. Wow.
Posted by: Matt Weaver | 16 August 2010 at 12:48 PM
Hate to break it to you, Matt, but TypePad automatically removed those extra spaces. Sorry.
Posted by: Ray Ward | 16 August 2010 at 02:04 PM
I can understand only using one space after a sentence if you are dealing with character limits, but in any other circumstance I truly believe TWO SPACES are essential. It's all about readability, enhancing comprehension and enabling breathing room. Two spaces makes text easier to read.
Posted by: Cara | 16 August 2010 at 04:53 PM
I can see the argument, but I think I'll stick with two spaces. I experimented by taking the second spaces out of something I wrote a while ago and I thought it looked crowded. I like the extra space as a way of separating sentences. And in the end, doesn't it come down to preference?
Posted by: Douglas | 18 August 2010 at 10:03 AM
Actually I’d say it comes down to two things: preference and readability. I haven’t found a scientific study comparing one space versus two for readability. So I follow the Chicago Manual of Style on this question.
Posted by: Ray | 18 August 2010 at 07:33 PM
I am another holdout on the two-space rule. I understand why journalists would drop to one when columns are short and space is at a premium. But I too think the extra space between sentences enhances readability, particularly in something like a brief. As one person commented on the related blog, a new sentence beginning with an abbreviation looks odd to me without the extra space,
". . . end. Dr. Derr said . . . ."
Posted by: Kristen | 23 August 2010 at 05:08 AM
The Seventh Circuit Court of Appeals' guidelines for briefs recommends one space as follows:
Put only one space after punctuation. The typewriter convention of two spaces is for monospaced type only. When used with proportionally spaced type, extra spaces lead to what typographers call “rivers”—-wide, meandering
areas of white space up and down a page. Rivers interfere with the eyes’ movement from one word to the next.
Posted by: Jim Covington | 30 August 2010 at 01:25 PM