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!
A. Technically, yes: two commas would still be considered correct. But the problem with that first comma—and the reason we discourage it—is that unlike dashes, semicolons, and opening parentheses, which are forward looking, commas tend to be backward looking. For example,
The committee, that is, its more influential members, wanted to drop the matter.
Does the phrase “that is” in the example above belong with the words that come before it, or does it belong to the words that follow? A stronger mark solves this potential for a momentary misreading by providing more structure to the sentence:
The committee (that is, its more influential members) wanted to drop the matter.
Another solution is to simply omit the second comma:
The committee, that is its more influential members, wanted to drop the matter.
That last approach is fine for casual prose, but formal prose usually calls for the more structured punctuation choices recommended in CMOS.
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?
A. It may seem reasonable to add a second comma, as Chicago would advise in similar scenarios—for example, after a year when it follows a day: “July 7, 2020, was a Tuesday.” But those two commas work like parentheses, which could be substituted for the commas without changing the meaning of the sentence: “July 7 (2020) was a Tuesday.” The comma in “11 minutes, 52 seconds” acts more like a conjunction, standing in for “and”:
The tortoise crossed the finish line 11 minutes, 52 seconds ahead of the hare.
or
The tortoise crossed the finish line 11 minutes and 52 seconds ahead of the hare.
A second comma is needed only if the sentence requires it for other reasons:
Beating the hare by 11 minutes, 52 seconds, the tortoise established a new record.
Other expressions that consist of a mix of related units may be handled similarly: “The team’s starting pitcher is five feet, nine inches tall.” But compare the case of a conversion, where the converted units must be fully set off from the surrounding text: “We drove 120 miles (193 km) before running out of gas,” or “We drove 120 miles, or 193 kilometers, before running out of gas.”
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.”
A. Every so-called comma splice is a conjunction away from conformity. As comma splices go, the following sentence would be considered a classic case:
Paul put the kettle on, Don fetched the teapot.
You can fix the transgression by adding a conjunction or by changing the comma to a semicolon:
Paul put the kettle on, and Don fetched the teapot.
or
Paul put the kettle on; Don fetched the teapot.
But some editors would argue that the version with the comma splice isn’t truly an error; it’s simply two independent clauses joined by a conjunction that’s been elided: “Paul put the kettle on, [and] Don fetched the teapot.” Such elision is more common in casual prose, but it does have its place, particularly in creative writing.
With a series of three or more independent clauses, on the other hand, it is conventional to retain only the final “and”:
Paul put the kettle on, Don fetched the teapot, and I made tea.
You could place semicolons between the clauses, but most writers and editors save those for more complex series (see CMOS 6.60). As for supplying the “missing” conjunction, that would be pointless.
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.”
A. Strictly speaking, the comma in your example is unnecessary. But such a comma may be added if the information that follows the conjunction needs emphasis or is intended as an afterthought—or, as in your example, to help readers navigate a hierarchy of alternatives by providing a sort of shorthand for “on the one hand . . . on the other.”
Even in the simplest of sentences, however, a bit of extra punctuation relative to an “or” or an “and” may be appropriate sometimes. Note how punctuation (or its absence) changes the emphasis in the following examples:
I’ll take an apple or a pear.
I’ll take an apple, or a pear.
I’ll take an apple—or a pear.
I’ll take an apple (or a pear).
I’ll take an apple. Or a pear.
All of these are correct. The conjunction “or” separates the alternatives; adding a comma, a dash, parentheses, or a period emphasizes that break in subtly different ways. But don’t go overboard. In general, it’s best to take a light hand with any punctuation that might be considered optional. When in doubt, leave it out.
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.”
A. The presence or absence of a comma after “of course” can make a difference, and any source (including your grammar checker) that suggests “of course” always needs to be followed by a comma is wrong. Though a comma can usually follow an introductory adverbial phrase like “of course,” such a comma is also usually optional (see CMOS 6.31). Of course, setting off a phrase like “of course” will emphasize the phrase itself. But to shift the emphasis to include the words that follow, you should omit the comma. (Of course you should.)
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?
A. Our recommendation depends on the idea that “Inc.” isn’t truly a formal part of a company’s name (in spite of what some companies like to think). It is, rather, a description that attaches to the formal name but is itself generic—every bit as generic as your example, “an incorporated company.” In just about the same way, “Jr.” and “Sr.” function as generic but capitalized additions to a person’s name; they signal a relationship to a parent or child with the same name, but they are not intrinsic to any one name.
A comma in the title of a novel or other work, on the other hand, belongs to that title: it can’t be deleted as a simple matter of style, as we recommend doing before “Jr.” or “Inc.” (see CMOS 6.43 and 6.44). Nor does such a comma bear any syntactic relation to the surrounding text. The fact that titles of works are usually cordoned off from the surrounding text by italics or quotation marks supports this logic.
If you’re still not convinced, and if dropping the first comma isn’t an option (some companies will insist), follow the logic of titles of works and omit the second comma. Any logic, as long as you adhere to it consistently, is better than none.
Q. Hello! I have a comma question. Which is the preferred punctuation: Amherst, Massachusetts’ Emily Dickinson . . . OR Amherst, Massachusetts’, Emily Dickinson . . . ? Recasting the sentence is not a useful option because there is a longish list of names and places: Long Branch, New Jersey’s Bruce Springsteen and Lachine, Quebec’s Saul Bellow and . . . Thanks.
A. Rewriting to avoid the possessive is (almost) always an option; that’s what “of” is for. Try “Emily Dickinson of Amherst, Massachusetts; Bruce Springsteen of Long Branch, New Jersey; etc.” Parentheses are another useful alternative: “Emily Dickinson (Amherst, Massachusetts)” (or vice versa). But if you must stick to the possessive, you have our permission to drop the second comma (the one after the state or province) as a reasonable exception to Chicago’s preference for commas in pairs, a preference that applies also to dates (see CMOS 6.17 and 6.38–39). Note that Chicago style for the possessive form of Amherst’s home state requires an apostrophe and an s: Massachusetts’s Emily Dickinson (another incentive to avoid the possessive).
Q. Is it correct to use commas before and after “myself,” “himself,” “herself,” “itself,” etc. in cases like “I, myself, wouldn’t wear that dress”?
A. Normally such commas would be unnecessary. When it repeats the subject, a word like “myself” is called an intensifier—it adds emphasis. Commas would draw even more attention to the subject, but unless you want readers to pause over that intensifier, leave them out.
Q. Why does a comma follow Washington, DC, in running text?
A. That second comma helps to set “DC” off from the surrounding text; together, the commas work like parentheses. (Like parentheses, such commas always come in pairs.) Consider that without the second comma, a misreading is possible. For example, “Washington, DC is a great city” might mean that you are telling someone named Washington that DC is a great city. Another option is to omit both commas: “Washington DC is a great city.” That’s US Postal Service style for mailing labels, but it’s not Chicago style for running text (though maybe one day it will be).
Q. I’m not sure when to use a comma following a date at the beginning of a sentence. Can you help? For example, “In the 1960s, McManus declared victory . . .” or “In 1967, McManus selected Jones as the victor . . .” A fellow editor suggests striking all of the commas that follow the dates.
A. Your editor friend’s suggestion is reasonable, and Chicago recommends much the same approach (see CMOS 6.31). But it’s also reasonable to disagree in certain cases. Wherever a comma might be helpful for clarity (or for emphasis), add one: for example, “By 1967, 357 residents had returned to the complex.” (That comma keeps the numerals from appearing to run together.) In general, a flexible approach will serve the reader better than a rigid one.