The em-dash is one of my favorite punctuation marks. No worries if you have no idea what an em-dash is. I didn’t either until I became an editor. Well, I knew what it was, I just didn’t know its name.
I love the em-dash because it’s got some pizazz. As a reader, it catches my eye and makes me pay attention to what follows it. As a writer, I can use it to slow a moment down fast, to create a mood, and to guide the readers’ attention to a detail I don’t want them to miss. The em-dash can’t be ignored.
The em-dash looks like this: — .
It is often confused with the hyphen (-) and the en-dash (–). But the em-dash (—) is longer than the hyphen and the en-dash. In the old days of typesetting, the em-dash was the width of the letter M, hence its name.