Em dash (Em rule)

  • An em dash (—) is longer than an en dash (–) and three times as long as a hyphen (-). Don’t be afraid of it. It is useful and versatile, and too few writers make use of it.


    Uses of the em dash

    1.  Em dashes set apart parenthetical phrases or clauses in a sentence. In this use, em dashes are similar to commas and parentheses, but there are subtle differences. For example, em dashes are used when a parenthetical remark contains an internal comma or would otherwise sound awkward if enclosed by commas. Perhaps a useful way to think of the em dash is as a pause or parenthesis with somewhat more emphasis than a comma and somewhat less than parentheses. Here are a few examples of em dashes used well for this purpose:

    Steely Dan’s title track to FM—a justly forgotten, Robert Altman-inspired 1978 comedy that tries to pass off Foreigner, Foghat, and REO Speedwagon as paragons of rock rebellion—initially sounds like an extension of that movie’s middle-of-the-road sounds. [AV Club]

    Since 2007, the consensus of the economic establishment—bankers, policymakers, CEOs, stock analysts, pundits—has been catastrophically wrong. [Slate]

    Both Dagan and Diskin oppose military action against Iran unless all other options—primarily international diplomatic pressure and perhaps sabotage—have been exhausted. [Guardian]

    In other cases, em dashes can go where parentheses would be too strong a break in a sentence, for example:

    The president’s nephews—sons of his late brother—include Amar, the deputy director for national security … [New York Times]

    2.  An em dash can indicate a sudden break, an interruption, or a trailing off, for example:


    HOWARD:  …  She’s totally unapologetic, she’s—
    CHEW-BOSE: She’s everything. [Interview Magazine]

    3.  Em dashes can replace colons or serve as harder versions of commas (similar to semicolons). While parenthetical em dashes often operate in pairs (see the examples under the first point above), hard-comma em dashes often function alone at ends of sentences, for example:

    The all-renewable energy sector is 30 years away — and always will be. [Salon]

    It’s that time of year again—time for New Year’s Resolutions! [Pegasus Books]

    Em dash typography

    Publications make varying style choices when it comes to rendering the em dash. Some use the equivalent of three linked hyphens surrounded by a space on each side (like — this), and some omit the surrounding spaces (like—this). Others, like the online New York Times and most non-U.S. publishers, use an en dash (or the equivalent of two hyphens) surrounded by spaces (like — this). Some use an en dash with no spaces (like–this). Others, such as the BBC online, use a hyphen surrounded by spaces (like – this). The hyphen is traditionally regarded as a poor substitute for the dash, but given the relative ease of typing the hyphen, its use in lieu of the dash seems to be on the rise, and many see nothing wrong in it. Ultimately, it is a matter of editorial preference.

    In Mac OS X, an em dash can be typed very easily by holding down the option and shift keys and typing a hyphen.

    In Microsoft Word, an em dash can be typed with ctrl + alt + numeric hyphen. Note that this is only available using the hyphen on the numeric keypad not the main keyboard.  Word (on a Mac or a PC) will automatically render an em dash when two hyphens are typed, unspaced, between words.


    1. Don’t you think the use of a single hyphen instead of an en and em-dash on blogs has something to do with the writing interface found on these free blog-sites? I remember, some of them do not work like MSword, where two hyphens would automatically be converted to an en-dash. So, I think that maybe most bloggers find it awkward to see a double hyphen, like–this, or a triple hyphen, like—this, to represent the most common dashes. Looking at it this way, they are probably trying to emphasize the hyphen by surrounding it with spaces in order to indicate that it is either an en or em-dash depending on the context. Of course, it’s just a guess. Interesting, though.

    2. The problem with the simplistic rules of using an em dash or en dash as presented here is that on a computer screen the dash may randomly appear at the end or start of a line, depending on how lines wrap as the text is edited, or the width of the browser window when the text is presented on the Web. Professional typesetters avoid putting dashes at the start of a line, as it disrupts rapid reading and comprehension of text. While most word processors and Web browsers that I’ve encountered over the last decade will break a line of text after an hyphen, they generally don’t respect that rule for em dashes and en dashes.

    3. Katie Coyle says

      Thanks, Grammarily. Very enlightening. I love learning new things about writing & using correct punctuation.

    4. Not to nitpick, but in #2, “trailing off” is used as a compound noun, and so should have a hyphen between them.

    5. Thanks for the comprehensive explanation. May I ask if the following usage is correct ?

      Globalisation has given each country a free rein in focusing its comparative advantage – industries which a country has strength in – to maximize profit.

    6. Before word processors there were typewriters which used two dashes, like — this.

      • Bren McDonnall says

        Many thanks. I’ve been struggling with this issue for years now. Seriously. Between this article and your reply, I think I may finally be able to stop going back over hundreds of pages and repeatedly changing the mechanics of usage for the em dash. Having learned to type in the ’60’s on an IBM Selectric, however, I don’t believe I’ll ever stop double-spacing between sentences. These days, it’s as instinctual as breathing.

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