H.S. Cross, author of "Grievous," discusses how and why she uses em-dashes—instead of quotation marks—to represent conversation in her writing.
Like many people, I first encountered dialogue set off with em-dashes (sometimes called quotation dashes) by reading James Joyce’s "Portrait of the Artist as a Young Man." I was a teenager at the time, and impressionable. Certainly, this way of styling dialogue was new to me, but I never had any issues knowing who was talking in this format. It may or may not be wise to let teenagers read Joyce, but for me the damage was done; my sense of how consciousness could appear in prose had been given a blast with a blowtorch.
Joyce didn’t invent em-dash dialogue styling—it was already being used in continental literature, particularly French—but he brought it into the mainstream of English literature. With it came Joyce’s intense interior access, and the exciting sense of flow that he and other modernists achieved.
When, as an adult, I began to work on the material that formed my first two novels ("Wilberforce" in 2015 and "Grievous" in 2019), I found myself presenting the dialogue with em-dashes. The few times I experimented with switching back to quotes, I felt dizzied by the clutter on the page. Once I got into the habit of cutting into speech with em-dashes, quotation marks had come to look very busy. As well, both of my novels are set between the wars at a fictional boys’ boarding school in England, a time and place linked in my mind to the worlds of Joyce and other em-dashers. When I made the decision to stick with this dialogue style, however, my em-dash radar had widened beyond Joyce to other, later, British and American examples such as Roddy Doyle’s "Paddy Clarke Ha Ha Ha" and Charles Frazier’s "Cold Mountain."
The em-dashes convey a sense of speed and pace better than quotation marks, especially when there is interruption.
Previously on Grammar Girl, Christopher Yates wrote a fantastic, wide-ranging essay about different dialogue styles, including his favorite, bare dialogue (a la Cormac McCarthy), in which dialogue is presented as just another paragraph with no styling whatsoever. In contrast to the “bare” style, em-dash dialogue feels louder because the speech is set off from the prose with that sharp little line. It can even start to resemble playwriting, especially with extended stretches sans dialogue tags, almost as if you’re reading a script with some stage directions tossed in. The em-dashes convey a sense of speed and pace better than quotation marks, especially when there is interruption.