Punctuation

Q. I’m editing a transcript, and our department’s lead editor is giving me some trouble. We’re suffering over the word so. Under what circumstances can one put a comma after so? For example, in this transcript, a woman says: “So great answer.” Is so functioning conjunctively here, or can it be treated as an interjection? And what, if anything, does that mean for comma placement?

A. Is there a recording, or did someone actually hear the woman speak? To deduce the part of speech, you have to know the intonation and pacing. Was the speaker referring to a “so great answer” with no break between so and great? Or did she say “so, [pause] great answer!”? The first use is adverbial (so modifies great) and would not take a comma, whereas the second is a kind of conjunction (an introductory particle) after which a comma would be helpful in indicating a pause. An ellipsis or dash might be even better. But if you don’t have a recording, there’s no way to decide the punctuation, unless you can guess from the context.

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]