Q. Hello! You have a Q&A where a speaker interrupts their own dialogue with an em dash, and your example uses a space before the new sentence: “I thought I might— Oh, it’s no use.” While I understand the logic of the space (the first sentence has ended suddenly; a new one starts), in practice, is there a justification for just closing up the spaces with all such em dashes for expediency and consistency, even if what follows is a complete sentence? Our global manuscript cleanup process would remove that space even if the author had written it in, and I am reluctant to have copyeditors spend time adding the space back in on a case-by-case basis, agonizing over whether the next clause merits a space and a cap (if it’s ambiguous), and so on. Is there room for a house style exception on this, or do you think that the space should be followed as a matter of Chicago style? Thank you for any help!
A. That space after the em dash in “might—” isn’t technically Chicago style; it’s not currently covered in CMOS itself (as of the 18th edition). But as our Q&A implies, we do think the space (followed by an initial capital) is useful—as does Benjamin Dreyer, the author of Dreyer’s English (Random House, 2019; see p. 124).
Still, it’s a small detail that isn’t likely to be missed if it’s not there in the first place. But if you do make an executive decision to clean out spaces after em dashes, consider changing the initial capitals that follow them to lowercase (except in proper nouns or initialisms or the like); absent that space, a capital may look to some readers like a mistake (though maybe less so in styles that put a space before and after a dash):
“I thought I might— Oh, it’s no use.”
becomes
“I thought I might—oh, it’s no use.”
not
“I thought I might—Oh, it’s no use.”
The first example is arguably best; it conveys the self-interruption more definitively than the others do. But if your editing resources are limited, this is one detail that, again, could be left on the cutting-room floor. Just be sure to alert your authors to what you’ve done when you return their copyedited manuscripts for review; they should get a chance to restore any spaces plus initial capitals that they think are mandatory.