Q. I work with many first-time authors, and many of them want to argue about commas. Of course as author, they have the final decision of their own work . . . but I keep running into the idea of breath: “My high school English teacher taught me that commas go where you want to take a breath, so that’s why this comma should be here.” What would you say to these authors?

Q. Chicago says commas aren’t needed with “not only . . . but also” constructions but are needed between two independent clauses joined by a coordinating conjunction. So which wins when you have both?

Q. Hi. A fiction author of ours hates the word that and often replaces it with a comma. For example: “The interior was so dark, she made out only shadowy shapes.” And “Her eyes fell on a cup, and a memory rose up with such clarity, she released a little gasp.” In such cases, we might offer her suggestions to rephrase, but would you let the commas stand? Or would you consider these sentences to have comma splices? This comes up a lot in fiction with other authors, too, so we’d love to hear your opinion! Thanks.

Q. Can you clarify when commas should be used with an “or” phrase? For example, should it be “Table salt, also known as sodium chloride or NaCl” or “Table salt, also known as sodium chloride, or NaCl”?

Q. According to CMOS 6.51, “Expressions of the type that is are traditionally followed by a comma. They are best preceded by an em dash or a semicolon rather than a comma, or the entire phrase they introduce may be enclosed in parentheses or em dashes.” My question is this: Would it still be acceptable to use a comma in such expressions rather than the em dash or parentheses? Thank you!

Q. When an expression like “11 minutes, 52 seconds” occurs in the middle of a sentence (as in “We finished 11 minutes, 52 seconds ahead of the next car”), is a second comma required? If not, why?

Q. I don’t understand why the following example in the serial comma section (CMOS 6.19) is not considered a comma splice: “Paul put the kettle on, Don fetched the teapot, and I made tea.”

Q. I’ve gone through your section on commas numerous times, yet I can’t seem to find whether a comma would be used in the following instance: “You can be very helpful to your mother or father, or to a person you think of as a parent.”

Q. Regarding the placement of a comma after “of course,” I’d always treated “of course” used emphatically differently from “of course” used as an aside. With the emergence of better grammar checkers being utilized with an assumption of accuracy, I now see more of this: “Can I come over?” “Of course, you can.” Is this actually correct? I’ve been unsuccessful in finding a conclusive answer. Some sources say you always put a comma after “of course.” Others say it’s up to the author. Since it seems that the placement of a comma can change the meaning, I’d hoped for something a bit more definitive than “You do you, boo.”

Q. In previous Q&A entries, you’ve said to include a comma after “Inc.” or “Ltd.” if a comma precedes it: “The office of ABC, Inc., was located downtown.” I could understand the reason for this if “Inc.” were replaced by a generic description: “The office of ABC, an incorporated company, was located downtown.” But since “Inc.” is a capitalized part of a formal, proper name, wouldn’t this be analogous to the example in CMOS 6.17 about titles of works, in which a title containing a comma doesn’t need to be followed by a comma (“Look Homeward, Angel was not the working title of Wolfe’s manuscript”)? If not, what’s the distinction?