What is a dash—and what isn’t?
There are three versions of the dash—but here’s the good news: no one except copy editors needs to know more than two of them.
It’s the short one: the mark that you (or your word-processing programs) make at the end of a line to show you’re break-ing a word when part of it has to bump down to the next line. The hyphen’s other job is to link compound words and adjectives. It’s the punctuation in decaf-skinny latte or hot-pink miniskirt or post-modern interpretation. Or word-processing program. To some extent this is a personal preference—there’s flexibility in when to use hyphens. Some people might say that postmodern (with no space or hyphen) is perfectly fine. However, hot pink miniskirt (with a space but no hyphen) is ambiguous; does it mean that almost neon bright shade, or a very sexy skirt that happens to be pink—or both?
One thing is certain, though—hyphens aren’t used as often as they used to be, and they’re tending to disappear. Many dictionaries and style books will tell you that the word good-bye, for instance, has a hyphen. But life, and usage, will tell you that goodbye is, well, good. So say goodbye to that particular hyphen.
The em dash
It’s the long one, conveying a rest or interruption in a sentence. On its own a dash often works rather like a colon or semicolon: take a look at the first sentence in the paragraph before this one. Two dashes—one at each end of part of a sentence, like this—help set that section apart and make the components easier to take in, especially if the sentence is a long one. It’s the same kind of job done by pairs of commas or, sometimes, parentheses. Dashes, though, make for a more emphatic break. Dashes are also a favorite tool of magazine writers, often used to wind up a piece with a cute or witty sentiment—the kicker.