The Long and Short of It

No, I’m not going to make short people jokes (I’m sensitive that way!).  Let’s make some hyphen jokes instead. 

Umm…I can’t think of any hyphen jokes.

Okay, instead let’s talk about the difference between a dash, en dash, and em dash. (And have you even ever heard of a 2-em dash or a 3-em dash?)  Turning your trusty copy of the Chicago Manual of Style to section 6.75, you see the following:

Hyphens and dashes compared

Hyphens and the various dashes all have their specific appearance (shown below) and uses (discussed in the following paragraphs). The hyphen, the en dash, and the em dash are the most commonly used. Though many readers may not notice the difference—especially between an en dash and a hyphen—correct use of the different types is a sign of editorial precision and care. (And hey, I'm all about editorial precision and care!)

hyphen -

en dash –

em dash —

2-em dash ——

3-em dash ———

A hyphen is used in compound words and names and in word division. A hyphen is used to separate numbers that are not inclusive, such as telephone numbers, social security numbers, and ISBNs. It is also used to separate letters when a word is spelled out letter by letter, in dialogue, in reference to American Sign Language, and elsewhere. Hyphens can also appear in URLs and e-mail addresses. A hyphen must not be added to such a string when it breaks at the end of a line.

The principal use of the en dash is to connect numbers and, less often, words. With continuing numbers—such as dates, times, and page numbers—it signifies up to and including (or through). For the sake of parallel construction, the word to, never the en dash, should be used if the word from precedes the first element in such a pair; similarly, and, never the en dash, should be used if between precedes the first element. In other contexts, such as with scores and directions, the en dash signifies, more simply, to.  An en dash may be used to indicate a number range that is ongoing—for example, to indicate the dates of a serial publication or to give the birth date of a living person. No space intervenes between the en dash and the mark of punctuation that follows. The en dash can be used in place of a hyphen in a compound adjective when one of its elements consists of an open compound or when both elements consist of hyphenated compounds. This editorial nicety may go unnoticed by the majority of readers; nonetheless, it is intended to signal a more comprehensive link than a hyphen would. It should be used sparingly, and only when a more elegant solution is unavailable. The en dash is sometimes used as a minus sign, but minus signs and en dashes are distinct characters (defined by the Unicode standard as U+2212 and U+2013, respectively). Both the characters themselves and the spacing around them may differ; moreover, substituting any character for another may hinder searches in electronic publications. Thus it is best to use the correct character, especially in mathematical copy.

The em dash, often simply called the dash, is the most commonly used and most versatile of the dashes. Em dashes are used to set off an amplifying or explanatory element and in that sense can function as an alternative to parentheses, commas , or a colon —especially when an abrupt break in thought is called for. An em dash is occasionally used to set off an introductory noun, or a series of nouns, from a pronoun that introduces the main clause. An em dash or a pair of em dashes may indicate a sudden break in thought or sentence structure or an interruption in dialogue. (Where a faltering rather than sudden break is intended, suspension points may be used.) An em dash may be used before expressions such as that is or namely. In modern usage, if the context calls for an em dash where a comma would ordinarily separate a dependent clause from an independent clause, the comma is omitted. Likewise, if an em dash is used at the end of quoted material to indicate an interruption, the comma can be safely omitted before the words that identify the speaker. In modern usage, a question mark or an exclamation point—but never a comma, a colon, or a semicolon, and rarely a period—may precede an em dash.

A 2-em dash represents a missing word or part of a word, either omitted to disguise a name (or occasionally an expletive) or else missing from or illegible in quoted or reprinted material. When a whole word is missing, space appears on both sides of the dash. When only part of a word is missing, no space appears between the dash and the existing part (or parts) of the word; when the dash represents the end of a word, a space follows it (unless a period or other punctuation immediately follows). Although a 2-em dash sometimes represents material to be supplied, it should not be confused with a blank line to be filled in; a blank in a form should appear as an underscore (e.g., ____).

In a bibliography, a 3-em dash followed by a period represents the same author or editor named in the preceding entry.

When I'm proofing a manuscript, I often find myself fixing hyphens to em dashes.  I do this by using the alt code for it.  Simply put, I hold down the Alt key and type 0151 while that Alt key is still held down.  This way, I know for sure the author will have a true em dash, not just what looks like a em dash. 

And I have to say, I love the versatility of the em dash.  When one character interrupts another-time for an em dash.  When a character's dialogue is stopped short by something they see-time for an em dash.  When it's time for an appositive-you know, something too good to leave out-time for an em dash. 

And to reward you for reading this entire post, here's a little something that made me smile.  Of course, I'm just twisted that way.

Want to learn more exciting rules for punctuation? Check out the Chicago Manual of Style, 16th Edition.  Or, you know, hire a freelance proofreader like me AND I'll look up all the rules!