Commas

A. It can be hard to ignore Microsoft Word’s blue underlines, especially when they’re worded in a way that suggests you’d be wrong to keep the text as is: “After an introductory word or phrase, a comma is best.”

But you can tell your author that we agree with you. In the words of CMOS 6.34, “Although an introductory adverbial phrase can usually be followed by a comma, it need not be unless misreading is likely. Shorter adverbial phrases are less likely to merit a comma than longer ones.”

The adverbs yesterday, tonight, and today aren’t phrases, but each of them derives from one (yesterday comes from Old English giestran dæg), and it’s clear that each is grammatically equivalent to a phrase like next week or in 1965. Plus, any one of these words would qualify as short in the context of introductory adverbial phrases.

To be fair to Word, tonight is the only one among the words and phrases mentioned above (from yesterday through in 1965) that Word’s grammar checker flagged in our tests when it wasn’t followed by a comma (as of July 1, 2025). Conversely, Word didn’t stop on any of them when they were followed by a comma. So it’s not that far out of line with CMOS.

Tip: To avoid falling under the influence of Word’s blue underlines, some writers prefer to toggle them off as they draft. A convenient way of doing this is to add a button to the ribbon. In Word for Windows (the desktop version), go to File > Options > Customize Ribbon. Then select All Commands under “Choose commands from” and scroll down until you find Hide Grammar Errors. You can then add that command to a new group under the Home tab (or wherever you want it to appear). Steps for Word for Mac will be similar.

If you use the option under Customize Ribbon to assign a keyboard shortcut to the equivalent command (look for ToolsGrammarHide under the All Commands category in the separate dialog box for keyboard shortcuts), keep the button, which has the important advantage of showing whether it’s on or off (via shading/outline).

[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]

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.]

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.]

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.]

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.]

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.]

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.]

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.]

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.]

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.]