This is part four of a four- or five-part series on dashes and hyphens that is intended to replace an earlier article.

Part one deals purely with the mechanics of producing a given dash/rule/sign/glyph in a document using four MS Office products; Word, Excel, Powerpoint and Publisher. Part two deals with hyphenation, the different kinds of hyphen, and how and where to use hyphens. Parts three deals with the En dash. Part four (this part) deals with the em dash.

What Is an Em Dash?

Visually, it’s a horizontal line whose length is (or was) equal to the width of an “m” in the typeface being used. Today, it’s defined as being the same length as the height of the font in use.

Part one of this series includes a chart that allows you to compare the relative lengths of the hyphen, the en dash, the em dash, and a couple of other “dashing characters”.

My issue with the em dash is that it’s the ugly stepsister of punctuation—it looks abnormally long in proportional typefaces. It really doesn’t look attractive to my eyes.
One person’s negative is another’s positive though. Lynn Truss, author of the eminently entertaining and much-quoted Eats, Shoots and Leaves [comma optional], points out that it is easy to see: “the handsome horizontal dash is a lot harder to miss”. She also refers to the em dash as the “mark à la mode”, pointing out that it’s used in texts and emails to connect disorganized thoughts, and that it’s difficult to use wrongly.

How to Type an Em Dash

In Word, Powerpoint or Publisher, you can type an em dash by typing two hyphens with no space between or on either side.

If you want to type an em dash in Excel, you have to use the Insert | Symbol menu options.

More details can be found in part one of this series of articles.

When to Use an Em Dash

The em dash is really versatile—it’s the Leatherman™ in the punctuation toolbox. Here are some of the many ways in which it can be put to work.

To draw attention to a phrase—one that you want to stand out—use em dashes. But don’t overdo it; according to New Hart’s Rules, you should limit yourself to one pair per sentence.

Dashes emphasize the phrase, whereas brackets (aka parentheses) subdue it. Here’s the same sentence with brackets.

To draw attention to a phrase (one that you want to stand out) use em dashes.

Note how the corralled phrase reads differently in your head.

To indicate an aside or afterthought, use an em dash—especially if you want to convey a more casual tone. In formal writing, a colon may sometimes be more appropriate, although the guidelines for colon placement open up a whole new can of words (not a typo).

To indicate a pause or break in direct speech, use an em dash. For example, “I always misuse—I always used to—I frequently misused em dashes.”

To set off dialogue à la mode de some European languages, start each speech in its own paragraph with an em dash.

In the same way that over-reliance on a multitool can lead to tears (or skinned knuckles, broken blades or rounded nuts), using too many em dashes can lead to tears of frustration on the part of the reader, who might easily lose the main message you’re trying to convey. This article is deliberately written in a style that, like a drinking binge, will have you declaring “never again!” Hence the above-referenced caution for restraint in New Hart’s Rules.

Opinion Is Divided, However

Not all style guides advocate the use of the em dash in all the above situations. New Hart’s Rules, The Canadian Style and The Chicago Manual of Style do concur, but New Hart’s Rules cautions that many British publishers use an en dash with space either side as a parenthetical dash.

Therefore, UK writers should check any style guide that they are required to comply with in order to confirm which convention to use.

The Long and Short

The em dash is definitely underused. Most people would use a space-hyphen-space sequence where an em dash is appropriate, and most readers wouldn’t notice. This is most likely because the standard keyboard doesn’t contain a key that produces an em dash. Typewriters didn’t contain an exclamation mark until the 1960s—if keyboards still didn’t, people would not resort to whole platoons of exclamation marks in their texts and Facebook posts.

The easy way to determine if a hyphen or an em dash is required is to remember that hyphens connect or separate words whereas em dashes connect or separate phrases.

One last note: it used to be customary and correct to introduce a list with a colon and a dash, as in the following example.

The names of some months of the year originate from the names of Roman Gods:—January, March, May.

This style should now be avoided.

Please Help Improve Yonder Pedant’s Ramblings

• Did I miss a typo? (I’ll feel bad when you tell me, but I’d rather you did tell me!)
• Did I write something that makes you want to turn green and burst out of your shirt?
• Do you have any better examples that you would share and allow me to use?

If so, please let me know by leaving a comment.