A Hyphen Is Not a Dash
by Tina Blue
March 23, 2002
When you need a dash, for whatever reason, you need a dash--not a hyphen. There are two kinds of dashes: the n-dash and the m-dash.
The n-dash is called that because it is the same width as the letter "n". The m-dash is longer--the width of the letter "m".*
We use the n-dash for numerical ranges, as in "6-10 years." When we need a dash as a form of parenthetical punctuation in a sentence--as I have been using it rather freely already in this article--we use the m-dash.
The problem is, most of us can't produce a dash on our typewriters or keyboards. Microsoft Word and other word processing programs will sometimes recognize two successive hyphens--typed with no space between them--as an m-dash and translate the double hyphen into a respectable dash. But at other times--and for no reason that I can fathom--it fails to make the translation and I end up with a double hyphen rather than a true dash.
I used to know a series of keystrokes that would allow me to produce a genuine n-dash or m-dash at will on my old computer--but since my current machine usually makes the dashes for me, I have forgotten the sequence, and I honestly don't even know if it would work on the software I now use. Probably not.
But whether or not your word processor will create m-dashes by translating double hyphens or by responding to a series of keystrokes, it doesn't really matter. Just as we used to type two hyphens in a row--with no space before or after them and no space between them--to indicate an m-dash on our typewriters, a double hyphen is still universally recognized as an m-dash. (If you can't manage an n-dash for numerical ranges, the regular single hyphen is still your only option, though sometimes your word processing program will even recognize the hyphen between two numbers as an attempted n-dash and also make that translation for you.)
So when you do want an m-dash, please do not use a mere hyphen instead. It creates confusion--because a hyphen signals something quite different from what a dash signals-as you can see by the incongruity of the silly little hyphen I just used to set off this adverb clause.
One reason I have used so many m-dashes throughout this short article--and I have more than one reason--is to show you what I mean when I say that an m-dash is significantly longer than a mere hyphen.
Another reason--as you have probably noticed--is that Homestead won't make a true m-dash for me, so just by reading this article you will get to see how the double hyphen works as a dash--and how it is properly used.
My third reason--and by now you should fully appreciate its validity--is to prove that although the dash can be a useful and effective form of parenthetical punctuation, it is a rather heavy spice. It calls quite a lot of attention to itself--and therefore should not be overused.
You do feel I have gone a bit heavy on the dashes in this little article--don't you?