Many people learned to add two spaces to the end of each sentence which is now built in to their muscle memory. My father learned to type adding two spaces to the end of every sentence, they tried to teach that to me in computer class in middle school but since I had a lot of experience typing already without it I never felt motivated to change my habit to add two spaces. I never really saw the point, in most formats I can't see the two spaces.

Two spaces after each sentence comes from typewriters, where it supposedly looked better. On computers it made sense in the time of monospaced fonts, but with "modern" fonts being able to control the amount of space behind punctuation it's largely redundant.

Except for when you want to do diffs at the end of a sentence.

For me it's a holdover from a high school typing class, but I find it useful. I mostly write in LaTeX which just ignores the extras. On the iphone, two spaces are replaced by a period and a space, which is quite handy.

Good typography seems to dictate a wider space after a sentence than between words. So this is a typewriter habit to mimic that kind of thing (like the sibling noted).

Some people might prefer two spaces, but my understanding is that all authorities on “good typography” have standardized on one space:

https://practicaltypography.com/one-space-between-sentences....

Rendering engines can do anything they want. The question is about source representation only, for semantic purposes. That has nothing to do with output representation. Even practicaltypography completely misses that distinction.

You wouldn't publish anything with line breaks between sentences either. Double spacing or line breaks both work nicely for semantic purposes because html (or markdown which almost always ends up displayed somewhere as html) will ignore it.

Any print publishing software in the 21st century should be aware that two spaces in a prose text source is a hint for a sentence break, and treat it appropriately. They often apply custom spacing (slightly more than 1, but nowhere close to 2) between sentences anyway. Without the two spaces, they have to algorithmically guess at sentences. You just won't notice when there are sentence detection errors, unless you're a typography fanatic; who's going to notice 1 space instead of 1.2 or whatever the optimum happens to be?

Maybe I'm just being slow this morning, but isn't the fullstop the indication of the end of the sentence?

What extra information is encoded by fullstop + 2 spaces?

The period also indicates the previous word was abbreviated, or can be used in an ellipsis, probably other situations that aren't top of mind right now.

GP:

> Good typography seems to dictate a wider space after a sentence than between words.

You:

> Rendering engines can do anything they want. The question is about source representation only, for semantic purposes.

The thread you’ve commented on is literally about rendering, not source representation and semantics. I agree that you can use a double-space as a sentence delimiter, but we’re currently discussing whether it’s “good typography” to render it that way.

Your reply cited Butterick which doesn't distinguish the two issues. Every "authority" I've seen strongly admonish against the use of two spaces fails to make this distinction. Which is why I emphasized it.

I don't think there's much dispute that two spaces is too much in modern properly rendered prose, so I don't know who "we" is. (And anyone who does think two word spaces is just fine, would probably also agree that it should be configurable and not dependent on two spaces in the source text.)

If there's a text renderer out there that renders two spaces as two word spaces in prose, that should be patched, not writers' brains.

Take a ruler to some text that's traditionally typeset and you'll notice that the width of the whitespace after a sentence end is slightly wider than the space between words. That's either an em space or an en quad. Between-word spacing would be about 1/2 an en.

Studies examining whether or not wider spacing between sentences improved readability have been inconclusive.

There is one good reason to use two spaces between sentences, at least for text that's going to be processed automatically. It can be very difficult for software to know whether a given punctuation mark is the end of a sentence or something else, like an abbreviation. GNU Emacs, for example, is (or was) coded to recognize sentences by looking for two spaces after a ., ?, or !.[1]

1 https://www.gnu.org/software/emacs/manual/html_node/emacs/Se...

Those authorities on "good typography" are wrong. They prioritize text looking pretty over text conveying information clearly and accurately, and the world is worse off because of it. Two spaces as the sentence delimiter is superior in every way that actually matters, and I will die on that hill.

Interesting. I definitely respect Butterick’s opinions on typography.

Yeah I believe this is a generational thing. I learned double-space as well, but pretty sure not long after me they stopped teaching that, and I've totally stopped doing it.

Double spaces was the norm on (almost always monospaced font) typewriters [EDIT: in English]. I assume it lingered on computers until sometime in the 80s but was shifting especially once proportional fonts for written material (other than things like code of course) became the norm.

I couldn't tell you when I switched.

Double spaces was the norm for English. I understand it is considered mostly obsolete nowadays.

It has not been the norm for German ever.

Edit: Related discussion: https://news.ycombinator.com/item?id=22975299

I was taught to use double spaces in highschool typing class (we used electric typewriters with the buffer off). In the ~35 years since I have only ever met a handful of people, all older than me, who did it in practice.

I continued through university while using a computer to type things up, I'm pretty sure my thesis had double spaces after periods, written in WP. Once I graduated I dropped it pretty quickly.

Was there an early version of Word's spell-check-on-the-fly that underlined double spaces, or am I miss-remembering?

>Was there an early version of Word's spell-check-on-the-fly that underlined double spaces, or am I miss-remembering?

I don't remember that and I was a fairly early user of Word going back to DOS days although I rarely use it any longer.

Apparently you could set up one or two spaces depending on your preference, however recent versions of Word now mark double spaces as an error by default.

I've seen two spaces listed as a "resumé don't-do" cos it marks you as an oldster.

I am an oldster, but never used two spaces. Probably because I never did typing lessons at school (hell I don't think it was even an option at my schools - computers hardly featured either).

My résumé is in LaTeX, so they literally would never know.