Q. With coordinate adjectives separated by a conjunction, there’s no comma: “A stable and sensible approach.” I assume it would be the same for contrasting adjectives: “A sensible yet volatile approach.” Though if you wanted to emphasize the volatility, you might set it off with commas: “A sensible, yet volatile, approach.” Does this all sound right?
A. That sounds right to us, though whenever you interrupt an adjective-plus-noun construction with an intervening phrase set off by commas, the result tends to be a little awkward. If you want to smooth things out while keeping the emphasis on volatility, try rephrasing. For example:
an approach that’s sensible yet also volatile
a sensible approach, albeit a volatile one
Or you could embrace the interruption by applying something stronger than commas:
a sensible—yet volatile—approach
a sensible (yet volatile) approach
See also CMOS 6.51.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. In text, I write: “. . . a book titled, ABC Book.” But should I use the word “titled” or “entitled” in front of the title? Also, should the title be preceded by a comma, as I’ve done here? I’ve always included the comma, but that may not be correct. Please help. Thanks!
A. Both titled and entitled are correct, and in this context they mean the same thing. Normally, you can use titled—that is, unless you’re feeling entitled (the other meaning of that word) to use the slightly fancier-sounding entitled.
But omit the comma before the book title. Many writers assume that a comma is needed before the title of any book or other work mentioned mid-sentence, probably because the words in italics or quotation marks resemble quoted writing or speech. In other words, titled (or entitled) is often treated (incorrectly) like said would be.
Instead, you should save your commas for direct quotations introduced like the one in the third example below (but not the fourth one; see also CMOS 12.14):
I just started writing a book titled ABC Book.
and
The first chapter is called “It’s Now or Never.”
but
My publisher said, “It’s now or never.”
or
My publisher said that “it’s now or never.”
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Would you use a comma between two independent clauses that are both subordinate to the same “if”? For example, “The qualifying relative would have suffered if the waiver had been denied[,] and the applicant had not been present to help her through her cancer treatments.” I’m looking in CMOS 6.26, but the advice there doesn’t exactly match this situation. Could you please assist?
A. Good question! Though retaining the comma in an example like yours wouldn’t be strictly wrong, omitting it will help readers understand that both clauses following the subordinating conjunction if (“the waiver . . .” and “the applicant . . .”) depend on that same word. This logic would continue to hold if you were to invert the sentence (though a comma would then be required after the second if-dependent clause): “If the waiver had been denied and the applicant had not been present to help her through her cancer treatments, the qualifying relative would have suffered.”
See also CMOS 6.24 (commas with introductory dependent clauses) and 6.25 (commas with dependent clauses following the main clause).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I recently wrote a book where some headings listed tasks and challenges. For example, “Task 1, Learn as Much as You Can about the Disease” and “Challenge 1, Adopt a New Attitude.” Someone told me the punctuation was wrong and the commas should have been colons. I think that either commas or colons are correct. Am I right?
A. You are right—either mark is correct, but a colon isn’t the only alternative to a comma:
Task 1: Learn as Much as You Can . . .
Task 1. Learn as Much as You Can . . .
Task 1—Learn as Much as You Can . . .
Task 1, Learn as Much as You Can . . .
Those examples are listed in descending order of effectiveness. A comma would be most appropriate as sentence punctuation (and we’re styling task numbers like page numbers here; see CMOS 9.26):
Now let’s turn to task 1, “Learn as Much as You Can . . .”
In a heading or a list, either a colon, a period, or a dash—each of which creates a stronger break than a comma—would work a little better at making it clear that “Task 1” is an enumerator and not part of the enumerated item. So you’re not wrong, but your challenger isn’t entirely wrong either.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I can’t get a definite answer on how to punctuate a sentence that starts with “trust me.” For example, “Trust me, you don’t want to do that.” Would this be considered a comma splice? Would it be better to use a period or em dash, or is the comma okay? What about “believe me” or “I swear”?
A. Any phrase like “trust me” at the beginning of a sentence that is roughly equivalent to a “yes” or a “no” can normally be followed by a comma (as covered in CMOS 6.34):
No, you don’t want to do that.
is like
Trust me, you don’t want to do that.
whereas
Yes, I’ve edited the whole document.
is like
Believe me, I’ve edited the whole document.
and
I swear, I’ve edited the whole document.
You could use a stronger mark of punctuation for extra emphasis:
I swear! It’s not a comma splice!
or
I swear—it’s not a comma splice.
among other possibilities
But a simple comma will be the best choice in most contexts (and won’t get you in trouble for using a comma splice—at least not with us).
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. If you’re replying to someone and want to say thank you, would you write “Thank you John” or “Thank you, John”?
A. If you happen to know that the object of your gratitude is a stickler for vocative commas, then write “Thank you, John.” Otherwise (and unless the context is formal), feel free to leave the comma out, a choice that suggests a certain degree of spontaneity and a friendly disregard for the rules. But if you’re an editor of any kind, use the comma regardless of what anyone might think; you have your reputation to maintain. For more on these commas, see CMOS 6.53.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I’m having a difficult time finding a rule that governs afterthoughts. For example: “I told him I would pay my respects another time, if necessary.” Comma before “if”? Seems like there should be.
A. Anything intended as an afterthought should be preceded by a comma, or by some other mark of punctuation—a dash, for example (or parentheses). A period could also work. In your example, the comma before “if” is the only thing that tells readers that “if necessary” is an afterthought. So keep it, assuming that’s what you intended.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. I am having an argument with our law clerks. I do not believe that a comma is needed when referencing a date range—e.g., “The case was active from November 3, 2021 to November 30, 2022.” My law clerks insist that a comma belongs after 2021 (between the dates), and I say that when a date range is preceded by a preposition, a comma is unnecessary. Can you provide me with a definitive answer? Thank you.
A. Most style guides published in North America (where the “Month Day, Year” format is preferred) will tell you to use that second comma (the one after the year). This includes not only CMOS (see paragraph 6.38) but also the guides from the Modern Language Association (MLA), the Associated Press (AP), the American Psychological Association (APA), the American Medical Association (AMA), and the US Government Publishing Office (GPO). The guides from Microsoft and Apple also support this rule.*
The idea is that the year is parenthetical—November 3 (2021)—and in your example this usage is relatively straightforward. But when the date is used as a modifier before a noun, the result can seem awkward, and some guides—including CMOS (in paragraph 5.83)—recommend rephrasing if possible:
The January 10, 2023, decision was unexpected.
or, less awkwardly,
The decision of January 10, 2023, was unexpected.
As for legal contexts, The Bluebook (the legal citation guide published by the Harvard Law Review Association) doesn’t seem to specify how to punctuate dates outside of citations (where a comma might follow a year but for other reasons). But we’d be surprised if The Bluebook’s editors didn’t support the additional comma in a sentence like yours. (A look at the Harvard Law Review’s website suggests a preference for the second comma.)
Verdict: Your law clerks aren’t wrong in this case.
* MLA Handbook (9th ed., 2021), 2.13; AP Stylebook (56th ed, 2022), under “comma”; Publication Manual of the American Psychological Association (7th ed., 2020), 6.3; AMA Manual of Style (11th ed., 2020), 8.2.1.9; GPO Style Manual (2016 ed.), 8.53; Microsoft Style Guide, “Commas” (June 24, 2022); Apple Style Guide (October 2022 ed.), under “dates.”
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Do you place a comma between a book or article title and the word “by”? For example: “Pride and Prejudice, by Jane Austen, was published in 1813.” Some editors delete those commas, but to me they make sense. The author’s name often isn’t needed to identify the work, and the pause there feels natural to me. Please guide me with your editorial wisdom.
A. Commas are correct unless an author’s name is being used restrictively, as it is in both instances in the second of the following two examples:
Great Expectations, by Charles Dickens, has gone through many printings.
but
Now that I’ve finally managed to read Great Expectations by Charles Dickens, I’m ready to tackle Great Expectations by Kathy Acker.
In the first example, the phrase “by Charles Dickens” is nonrestrictive; omitting it wouldn’t change the meaning of the sentence (though not all readers will know who wrote Great Expectations). In the second example, omitting the authors’ names would obscure the intended meaning.
For more on the use of commas relative to restrictive and nonrestrictive phrases and clauses, see CMOS 6.27–29.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]
Q. Hi. I am editing a text and would like to know whether the following sentence should have a comma after the word “so”: “So let’s think about how to understand the chemical diversity of the 20 amino acids.”
A. The conjunction “so” can normally begin a sentence without the help of a comma—as can an introductory “and” or “but.” But that doesn’t rule out a comma in every case. Compare these two sentences:
“So where do you want to go next?”
“So, where do you want to go next?”
The comma after “so” in the second example puts the emphasis on that word, making it read as a sort of interjection. In fiction and related genres—particularly in dialogue—this distinction can be important. (See “ ‘Erg, no kidding?’ Interjections in Creative Writing” at CMOS Shop Talk.) In more ordinary prose, however (including your example), such a comma can usually be omitted.
Note that a comma is always omitted when the initial “so” is used as an ordinary conjunction in the sense of “with the result that” or “in order that” rather than as a purely introductory word:
So I wouldn’t miss my stop, I closed my book.
[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]