The enemy of grammar?

Lynne Truss, author of the punctuation guidebook Eats, Shoots and Leaves, says the em dash is “seen as the enemy of grammar.” Because it is both easy to use and difficult to use incorrectly, she seems to be saying that the em dash’s innate flexibility encourages people to break rules. She is likely referring to the common habit of sticking dashes wherever there’s a pause in thought. Many writers (even myself on occasion) are guilty, especially in informal writing, such as journals or personal emails.

So that you’re not a rule-breaker when it comes to the em dash, a closer look is in order.

The em dash can indicate an unfinished or interrupted statement in dialog:

• “Be careful. It’s slip—” he said, before falling into the lake.

It can separate an introductory series from the main part of the sentence:

• A wet dock, smooth shoes, a lapse in focus—now, there’s a recipe for a sudden splash.

Finally, and most commonly, the em dash sets off a word or phrase in a sentence—an interruption, in other words—in much the same way as do the comma and parentheses. The difference lies in the degree of intensity of the interruption. The comma is the least sudden break, the parentheses are in the middle and the em dash is the most abrupt.

• My uncle, who’s known for being clumsy, made quite a splash at the lakeside party.
• My uncle (who regularly embarrasses himself) made quite a splash at the lakeside party.
• My uncle—who’s kind of a jerk—made quite a splash at the lakeside party.

Ultimately, the choice will be a matter of your judgment and instinct, but if there is an element of surprise or a sharp change in thought, the em dash will convey just the right level of intensity.

When you do use the em dash, follow these guidelines:

• do not put a space either before or after the em dash
• avoid using more than one pair of dashes in a sentence

The em dash can be a wonderfully expressive tool. It conveys that break in thought, that surprising change in direction, like no other punctuation mark. Far from being the enemy of grammar, the em dash (used judiciously) can be a writer’s dear, dashing friend.