At our writing disposal are a preponderance of short straight lines:

  • Hyphen -
  • En dash –
  • Em dash —
  • minus sign −
  • Horizontal bar ―
  • Figure dash ‒

From what I've read, the em﹘ and en−dashes—in particular originated with typography. What is not clear to me is why so many variations were they created. This post–which makes a case against using them‐suggests that the em-dash itself is of nebulous origin―at least in terms of time.

Usage has been covered on this site and others (e.g. When should I use an em-dash, an en-dash, and a hyphen?) , but ‑where did they all come from and why the need for so many short straight lines?

  • 3
    Printers love fiddling around and trying to make their typesetting look perfect. Beats me why we ordinary folk who aren't professional typesetters need all three. While substituting a hyphen for a dash - like I just did - looks horrible, is there any real reason we need two different lengths of dashes? And I bet that in the old-fashioned days, printers had more than just em-dashes and en-dashes to work with. Dec 22, 2015 at 5:13
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    @PeterShor- is right. It’s not an English thing, it’s a typesetting thing.
    – Jim
    Dec 22, 2015 at 5:29
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    @RegDwigнt My point was that many of them look so similar that they can't be distinguished. To make that point, I intentionally used 9 different versions in the posted question. Can anyone tell the difference without looking at the source?
    – Minnow
    Dec 22, 2015 at 14:00
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    This might have to do less with your rep and more with the font you have installed, or the resolution you have picked. It is certainly possible to imagine circumstances in which it gets hard to distinguish an ſ from an f, or a þ from a p or a half note. However, for as long as you can distinguish an n from an M, it will by definition be fairly trivial for you to also distinguish between an en dash and an em dash. That's what the names mean. One is as wide as an n, the other one is as wide as an M.
    – RegDwigнt
    Dec 22, 2015 at 14:55
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    The original dash was an inked line in a handwritten script, and was as long as the author felt appropriate for the particular circumstance. Only when typesetting began did it become necessary to settle on specific lengths, and then you started to see some standardization. But by then the cat was already out of the bag. (And cats do not like to be put into bags.)
    – Hot Licks
    Dec 22, 2015 at 18:42

2 Answers 2


If you look at printing manuals from the mid-19th century (you can find these on Google books, for example Typographia: Or, The Printer's Instructor, from 1857) there wasn't any distinction between em-dashes and en-dashes when used as punctuation.

This book recommends using em-dashes—with no spaces to either side—to set off parenthetical comments, and also using em-dashes for ranges of numbers, like 33—47.

Printers also had dashes available in twice, three times, four times, and maybe six times the length of the em-dash (called a two-em dash and so forth), as well as the en-dash which was half the length of the em-dash. These were intended to be strung together so as to create horizontal rules of arbitrary lengths.


At some point, I assume that some printer decided that en-dashes—which were readily available because of their use for horizontal rules—looked better than em-dashes for ranges of numbers, e.g. 33–47. Other printers copied him because it did indeed look slightly better. This became enshrined as a tradition, and now standard English punctuation has two lengths of dashes, when one length would serve nearly as well, as it did in the 19th century, and be less confusing.

  • 1
    Interesting. Sounds like Darwinian evolution. Did you see any other notable forms of punctuation that didn't make the cut?
    – Stu W
    Dec 22, 2015 at 13:59
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    @StuW. In the early days of punctuation, the slash (/) was sometimes used in ways that are completely foreign to us now. Wikipedia says "In the early modern period, in Fraktur script, which was widespread through Europe in the Middle Ages, one slash (/) represented a comma, while two slashes (//) represented a dash." A similar convention (maybe the same one) was sometimes used in the early days of English printing, although I don't have a reference to it currently. Dec 22, 2015 at 14:06
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    And more evolution: Wikipedia says that the backslash (\) was introduced because somebody designing ASCII thought it was a good way to make the composite symbols /\ and \/, although it was also a mathematical symbol before that. But there are lots of mathematical symbols that never were adopted more widely. And after it was readily available in ASCII, it developed a number of uses. Dec 22, 2015 at 14:08
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    And a very nice article on the evolution of punctuation is here. Dec 22, 2015 at 14:21
  • Nicely done once again!
    – Minnow
    Dec 25, 2015 at 4:58

Those are printer's conventions. (In printer's lingo, an "em dash" is a dash the width of a capital M, and an "en dash" is a dash the width of a capital N.) Functionally, a hyphen divides a word by syllables (and may link words in a phrase to form an adjective), the minus sign indicates an arithmetic operation, and the rest are punctuation. If you were using an old-fashioned monospaced typewriter, you would type the hyphen and the minus sign as one dash and the rest as two dashes.

The distinctions are not linguistic, and each style book will take its own position.

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