I do, just like they taught me in 10th grade typing class. But a quick sample of my incoming e-mail suggests I’m the only one, apart from Mrs. Q and my mom. Mrs. Q informs me the APA styleguide demands one space after a period: she uses the double space in e-mail but not in papers. LaTeX splits the difference, using an intersentence space about half again as large as the space between words. The iPhone automatically drops in a period when you double-space after a word, which seems designed to suit habitual double-spacers like me; on the other hand, the text it actually produces has just one post-period space.
So I’m confused — has this tradition really fallen out of use and no one told me? Or was it never a tradition at all, outside my high-school typing class?
Quomodocumque 
Isn’t double-spacing after a period a relic of monospaced typefaces, made unnecessary (and, I would argue, ugly) with proportional spaced fonts?
It’s one space. The two-space thing is a relic of the typewriter age (and typing teachers who learned on actual typewriters).
http://en.wikipedia.org/wiki/Double_spacing_at_the_end_of_sentences#Origin:_the_typewriter
I create writing textbooks for Houghton Mifflin and we tell students that two spaces after a period should not be used.
The facts are as stated above, but I remain a firm advocate of two spaces. In HTML, it doesn’t matter what you do, as multiple spaces are always collapsed (except for a few over-enthusiastic conversion routines that convert space-space to nbsp-space). I think two spaces plain looks better. It’s one of those things, like whitespace around em-dashes.
Wait, there are people who don’t put spaces around em-dashes? Savages!
Two spaces!
I put two spaces after a period that ends a sentence, but not for one that’s part of an abbreviation. When reading a TeXed manuscript, I always notice when people have forgotten to put ties after their nonsentence ending periods…
I put two spaces after a period, through long-engraned habits reinforced by Emacs and TeX. Every once in a while, somebody on my Twitter feed goes on a rant against that, which has always struck me as odd.
I don’t put spaces around my em-dashes, though. Well, I do when writing in a character set that actually has them, I would probably put spaces around an ASCII dash.
Oh, sorry — spaces around em-dash means spaces around ASCII em-dash, as here.
It’s easy to see why Twitter people would oppose extra spaces!
I prefer a single space after a period. It looks more natural to my eye with well designed typefaces. Although convention dictates no spaces surrounding an em dash, I think it looks better surrounded by something like a \thinspace or \medspace. A full space surrounding an em dash looks excessive to me.
I was taught by my mom to put two spaces after periods. I only discovered about a year ago that other people only just one space, which struck me as odd…
I think I was one of the last generations to be taught to use two spaces. My younger acquaintances all seem to use one.
One space. I was told by some teacher or another that convention called for two, but I decided I didn’t like it and continued to use only one. Perhaps amazingly, I was never called on it.
Two spaces, of course!
1. I always type email with two spaces after each period.
2. In TeX, lots of authors leave inter-sentence spaces in the middle of sentences. I hate that. The people who type “$p-$adic” are worse, however.
3. It seems to me that most print publications don’t leave spaces on either side of emdashes. A \thinspace looks good to me. I cribbed the following code out of a document that I remember as having been written by Knuth:
\def\dash—{\thinspace—\hskip.16667em\relax}
You can code emdashes as “\dash—” and the right thing happens. I presume that the asymmetrical definition as something to do with line breaks.
I use two.
I use two spaces after a period.
I just checked the last email I wrote, and I used one space consistently. I was taught to use two, and did that for a long time, but then a few years ago my little brother told me it dated me. I kept using two for a while, but apparently I stopped at some point. Em-dashes in ASCII are tough. I think I usually use two hyphens with spaces on either side, though you can get bad line breaks that way. I make En-dashes in ASCII the same as hyphens, which is unfortunate, but such are the limits of ASCII. In TeX, I just use a triple dash for the em and a double for the en, no spaces, since somewhere I learned that that’s exactly how TeX was designed. (Am I wrong?)
My thesis advisor hated the default double spacing in TeX. I think he said it that was only in the US or perhaps the English speaking world where it was used. He always used the \frenchspacing option.
Hey, there’s a wikipedia page on “double spacing at the end of sentences”!
One space and my wife (who is a professional editor) agrees.
Two spaces here, and I understand it’s a relic. It’s all about the gravitas.
I use two. Because I am very, very old and actually learned to type on a typewriter. I think most people don’t notice one way or the other in email, and TeX does the right thing no matter how many spaces you type. But it looks strange to my eye to have the space between Mr. So-and-so and the space at the end of a sentence be the same. (Which, I know, you have to force the other way in TeX.)
I always use two spaces after a period. I learned to do it because it was one of the style guidelines for a student paper I worked for in the early ’90’s.
I tried going down to one space a couple of years ago (when I learned that two spaces after a period is no longer “in”), but I went back to the two-space thing because I think it looks better (even with modern fonts).
Two spaces after a period. I’m a young fogey — I learned how to type on a combination of a typewriter and a Commodore 64 (using an ancient word processor whose name I have forgotten), and on both two spaces were customary.
I secretly get annoyed at my coauthors who only use one space, and I have been known to waste time going through my joint papers “correcting” this…
I also learned to type on a typewriter and used two spaces for years. Then when I was editing a literary magazine, I was told publishers use one space for aesthetics (this was in the computer age) and to save space. So I switched and now use one space.
I added a few things… Check it out now.
http://en.wikipedia.org/wiki/Double_spacing_at_the_end_of_sentences
I’ve always done it this way (even before I learned LaTeX).
Two spaces!! But that’s because I write my e-mail in Pine, with a monospaced font. Annoyingly, Pine often rejustifies a paragraph upon sending it, and when a period in the input coincides with a line break, it introduces only one space. I’ve tried to customize this in vain. The argument for capitulating is that the recipient probably reads my e-mail in a proportional font.
Two years late to this topic I know, but it still is important as I’m looking again at this issue.
I think two spaces looks better also. In reading I get a better feel for the end of the sentence with two spaces, otherwise it looks just like another comma between the words. It doesn’t have that intentional break that one may use to take a breath when reading aloud.
And are not proportional spaced fonts in fact designed to replicate monospaced typefaces? In fact, when looking at the proportional spaced ‘space’, I find it much smaller than monospaced ‘space’. It is that much harder to distinguish the end of a sentence.
Two spaces is not a relic of the typewriter. Check out this article:
http://www.heracliteanriver.com/?p=324