In case you aren’t familiar with an em dash, I put it in the title as a visual aid. It’s name comes from it being the same width as the letter m; similarly, an en dash is the same width as the letter n. An easy way to find these symbols in Microsoft Word is to click on Insert>Symbol>More Symbols>Special Characters, and you will come upon a list with the em dash and en dash as choices (along with some other great symbols). In some versions of Word, there are keyboard shortcuts you can use to generate them; simply do a Google search to find out how.
Why It’s So Cool
The em dash is like the Swiss Army knife of punctuation. It can step in for a comma, a colon, or even parentheses. Just like commas and parentheses, it’s great for setting off extra details—whether that’s examples, explanations, or cool facts. And much like a colon, it’s perfect for introducing an explanation or expanding on what came before it.
I’m a bit of a minimalist when it comes to writing, and I feel it is best not to overuse nifty punctuation. In other words, your document shouldn’t be riddled with em dashes. Use them sparingly, like you would an exclamation mark. Too much of a special thing makes it ordinary, and you want those special punctuation marks to really stand out and make the kind of impact they are capable of.
Have you ever read a message with too many exclamation marks? Trust me, it ain’t pretty. Likewise, don’t overdo it with the dashes. Not counting the title, I used the em dash only once in this post. Given how much I like them, that’s showing some impressive restraint.
The En Dash
I typically only use an en dash to show a range of numbers or dates and in telephone numbers. For example, I went to high school from 1991–1995 (can you see how this dash is slightly shorter than an em dash but it’s longer than a hyphen?). As another example, I can still remember my home telephone number from when I was a kid living in Scotts Valley, California: (408) 438–6787. In later years, as the area grew, our area code changed to 831, and 408 was reserved for people living over the hill in San Jose, etc. Do you remember your phone number from when you were a kid?
The Hyphen
This is the most common dash (though it’s technically not a dash). It is used to join words. For example, my age is two numbers that need to be written with a hyphen to join them: forty-seven. Maybe you have a low-grade fever or perhaps you drive a car that takes high-octane gasoline. Hyphen time!