(source: grammarpartyblog.com)

First things first: hyphens are not dashes. There are actually three different punctuation marks that resemble a short horizontal bar positioned at midlevel: the hyphen, en dash, and em dash. They all function differently, so it’s important to get all the facts before you start ornamenting your content with hyphens and dashes.

Hyphenation for a Non-Hyphen Nation

A hyphen, the shortest of the three horizontal punctuation marks, mainly functions to connect compound adjectives and nouns. The connecting punctuation mark, found between the zero key and the equal sign on a standard keyboard, tends to be an inconvenience for writers, and cause tribulations for editors, especially on the web.

Internet writing, in general, calls for less punctuation. Sometimes new web writers confuse hyphens with dashes, and beyond this, hyphenated words are being phased out of our language. Change and confusion create ambiguity and unanswered questions. And in the world of web writing, it seems as though hyphen and dash issues are ignored rather than addressed.

The English language is constantly changing, so it only makes sense that words are continually phased in and out English dictionaries. As Simon Rabinovitch notes in an article for Reuters, an example of this phenomenon can be found in the 2007 edition of the Shorter Oxford English Dictionary, where over 16,000 hyphenated words were axed. Keep in mind that the British population tends to hyphenate more frequently, where Americans tend to hyphenate only when necessary.

In the SOED, formerly hyphenated word combinations blend together to form a single compound word, or split apart into two separate words without a hyphen. For example, cry-baby became crybaby and pot-belly became pot belly. Besides forming certain compound words, hyphens are also used for compound numbers and spelled-out fractions, such as “twenty-four” and “three-fourths.”

Hyphen Hang-Ups

Content writers usually think it’s the editor’s job to correct their hyphen hang-ups, and to an extent, they’re right. Editors know the grammatical rules that apply to hyphenated words, and they know that hyphens are required for compound modifiers that come before a noun. Putting the technical and grammatical terms aside, writers should know the difference between a hyphen and a dash, as well as how both function in a sentence.

Inexperienced writers often insert a hyphen instead of a dash, and this type of mistake causes content to lose its meaning, which in turn causes the author to lose credibility. (Not to mention that it’s aesthetically displeasing.) Take the following two sentences for example:

“Wait-please don’t go.” (Incorrect use of hyphen.)

“Wait—please don’t go.” (Correct use of em dash.)

The first sentence, using an incorrect hyphen, forces readers to form a relationship between the words “wait” and “please.” A properly placed em dash, on the other hand, creates a natural pause for the reader (a longer pause than what is created by a comma).

Mark my words: the meaning behind your words can change with or without a hyphen. Read the following two sentences:

“Wait! We forgot to stop at the giant trombone store!”

“Wait! We forgot to stop at the giant-trombone store!”

Wait—are we talking about a giant store that sells trombones, or a normal-sized store that sells giant-sized trombones? The essential hyphen lives on!

For more information on the correct use of hyphens, consult the Chicago Manual of Style. Also, fellow copy editor and writing blogger, m.e., provides an excellent collection of blogs addressing grammar blips, which includes an impressive compilation of blogs dedicated to hyphen issues.