Ode to the em dash

Shall I compare thee to a semicolon?

Thou art more lengthy and more versatile —

Though oft-sufficed by mere comma or colon,

Thou art most beloved by me (and AP Style).

My rhyming of “colon” with “semicolon” aside, the verse above surely betrays a passion few punctuation marks could hope to inspire — the passion inspired by a punctuation mark so tasteful, yet so flexible, that its devotees often find themselves wondering why they even bother with other, lesser marks. A mark — though tragically excluded from all standard keyboards — used by countless writers, reporters and students to add length and a probably-undeserved air of legitimacy to their writing. It is an elegant mark, for a more civilized age — the em dash.

As a testament to this versatility, in the above paragraph, I used em dashes in place of a comma, a pair of parentheses and a colon.

For those not in the know, the em dash is a punctuation mark appearing as a horizontal dash as long as the width of the font — traditionally the length of an uppercase “M.” It is not to be confused with its shorter, more lame, little brother, the en dash (“–”), and especially not to be confused with the hyphen (“-”), whose unique but near-exclusive use is in joining words together.

While I’ve mentioned the versatility of the dash, its range of uses is — unfortunately — finite. The most common uses are to indicate unnecessary or parenthetical information — such as I’m doing now — or to introduce a related clause or a list — typically the job of the colon. This is not to say, however, that the em dash is simply an interchangeable stand-in for other marks. On the contrary, while it may serve the same role as other marks, its effect is undeniably (though subtly) different — befitting its visual length, it gives the impression of a much longer pause than a comma or colon would, creating a greater sense of anticipation and importance. Used for parenthetical information, it isolates and emphasizes its contents much more than mere parentheses are capable of. In all uses, the em dash is slightly less formal and slightly more emphatic.

While I and everyone else who likes to act pedantic about punctuation may have their gripes with AP Style (the style guide used by most reputable American newspapers, including The Observer) for its tyrannical prohibition of the Oxford comma, I’ll give it credit for giving em dashes the respect and space they deserve — unlike most style guides, AP requires a space before and after the em dash.

If punctuation is to writing what percussion is to music, the em dash is an invaluable tool for writers to modulate the flow, tempo and mood of their writing. If I inspire even one person to try using an em dash, this column will have been a success — a world with more em dashes is a world I want to live in.