Hyphens and Dashes

What is the difference between a hyphen and a dash and when should I use them?
What is an “em dash” and what is an “en dash” and how do I use them?

1. hyphen (-) : Mac and PC: hyphen key: The hyphen connects compound words.

There are permanent compounds that have found their way into the dictionary (henhouse, makeup, notebook).

  • Kilowatt-hour, mass-produce, ill-favored, tie-in, toll-free call, two-thirds. A food-loving back-to-the-land generalist who became obsessed with fermentation

There are also examples when using a compound adjective before a noun.

  • A fast sailing ship. Or, a fast-sailing ship

2. en dash (–) : Mac: Option + – = – / PC “Alt” and type “0151.” The en dash connects things that are related to each other by distance.

  • Seven–ten days
  • You will find the article in the May–September issue of Scientific American
  • According to Frank Hanks, there should be a reference to what Edward Said calls “Orientalism” (147–48).

Or combining open compounds (note prefix connected to proper noun):

  • North Carolina–Virginia border
  • a high school–college conference
  • Post–Civil War

3. em dash (—) : PC “Alt” and type “0151” / Mac: Shift + Option + – = —. Em dashes may replace commas, semicolons, colons, and parentheses in apposite phrases, to indicate added emphasis, to interrupt or change thought:

  • “The Incompletion figured in the dash—is life” (McHugh 113)
  • Dickinson’s use of the dash—a mark of punctuation a reader encounters throughout her work—requires careful scrutiny
  • There is little room for error—whether one is consuming French fries or pork rinds.

(The practice of using two hyphens for a dash, although acceptable, is a holdover from the days of typewriters).