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Should there be a short or long hyphen separating the two words?

Non-residential vs non–residential

marked as duplicate by RegDwigнt Jun 8 '15 at 13:41

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up vote 1 down vote accepted

tl;dr: Use the hyphen.

I'm not sure EL&U typically addresses typesetting questions, which tend to be a matter of convention, stylistic choice, and or publisher mandate (i.e. house style), but this one seems fairly clear-cut.

According to the reference @Eilia supplied to the official Translation Bureau of the Canadian Government, there are three punctuation marks to consider:

  • The hyphen: -
  • The en-dash or "short dash":
  • The em-dash or "long dash":

The hyphen is the character found on the underscore key (_) on the standard American keyboard1. In the days of typewriters the em-dash was sometimes rendered as two hyphens (--), because the character is twice as long as the en-dash (i.e. the width of a M rather than an N), and every once in a while you'll see that convention used on the internet. But by-and-large today, both the en- and em-dashes are supplied by specialized desktop publishing software.

Let's dispose of the em-dash first. The em-dash is used exclusively for emphasis: a pair of em-dashes surrounding a clause are sort of like "negative parenthesis" — they draw attention to the clause, rather than downplaying it.

By contrast, both the hyphen and the en-dash are used to form compound modifiers, which is what you're asking about here. But the en-dash is only used to form compound modifiers when one of the components itself is compound, as in "post–World War I treaty", "sodium chloride–free solution", or "New York–based writer".

It is the hyphen which is used to form standard two-word compound modifiers such as "non-residential"2.

1 aka ANSI-INCITS 154-1988 (R1999)
2 Note that you only use the hyphen to form the compound modifier if that modifier precedes the word it modifies, not if it follows. In other words: "on-site facilities" but "facilities on site" (no hyphen nor dash).

  • You should copy and paste this answer on the duplicate, it's just as good as the single answer posted. Maybe add the OP's example in your answer, which clarifies your phrase "which is what you're asking about here." – Mari-Lou A Jun 8 '15 at 15:02
  • Thanks @Mari-LouA, but it would be a bit pointless. That other answer has a score of +140 and the question is very old. Even if I recapitulated this answer there, no one would ever see it (and it'd bump and old and already well-answered question to the front page, which is a peeve of mine). – Dan Bron Jun 8 '15 at 15:08
  • A good question with a good answer gets bumped to the front page. What's wrong with that? I like your answer, but it will gather cobwebs and dust if it's just left here. On the other hand, people will see the old question and read both answers, they might not be able to upvote either of them because they lack the rep, but it doesn't mean they won't find this answer helpful. It's useful to have two good answers, they complement one another. – Mari-Lou A Jun 8 '15 at 15:12
  • Great, detailed answer, but you've overlooked the fact that "non" is not a word—it's a prefix. Hyphens are not used to join prefixes to words in American English unless they resolve some kind of ambiguity. See – nomad Jun 26 '15 at 13:19

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