Commas

A. Not usually. For example, both of the following would be correct:

But I don’t want to meddle.

And to avoid getting my feet wet, I wore boots.

The rule is the same as when the conjunction introduces an independent clause within a sentence (usually following a comma; see CMOS 6.22):

I’d tell you how to punctuate this sentence, but I don’t want to meddle.

I carried an umbrella, and to avoid getting my feet wet, I wore boots.

but

I carried an umbrella and, to avoid getting my feet wet, wore boots.

It wouldn’t be strictly wrong to add a comma after the conjunction in the second and fourth examples (see CMOS 6.26), but Chicago usually prefers to omit it unless the conjunction joins a compound predicate (as in the fifth example; see CMOS 6.32). The same logic could be extended to similar constructions that might otherwise call for two commas. For example,

But Jerome, we haven’t yet discussed commas.

Some editors would add a comma before “Jerome” (see CMOS 6.53), but unless you’re applying or enforcing a comma-heavy style, you can omit it.

A. First, direct your publisher to CMOS 6.28, which says that Chicago doesn’t allow a construction like “My wife’s, Deb’s, father.” Then, point them to our recent (December 2020) analysis of the subject at CMOS Shop Talk: “Your Dog[,] Smurf: Understanding Commas with Appositives.” According to that post, so-called spousal commas can be omitted wherever they seem awkward or unnecessary. In sum, if your inclination is to write “My wife Deb’s father,” you have Chicago’s blessing.

A. The rules on comma usage in CMOS (chapter 6) favor writing over speaking. The goal is to provide readers with the minimum number of signposts required to navigate sentence structure. Sentence structure is logical. Pauses or breaths, on the other hand, tend to be personal. Though commas will often correspond to pauses, no two people will read the same sentence in precisely the same way.

For most types of expository writing, we’d advise following a consistent set of rules that assign commas based on sentence structure rather than pauses or breaths (or what some would refer to as rhythm). This approach will support the goal of producing clear, unambiguous prose.

But in fiction and poetry and other forms of creative writing, there’s more room for stylistic variation. Some writers apply commas with a light touch; others punctuate more closely. Henry James was a stylist of the latter type:

It led, in short, in the course of the October afternoon, to his closer meeting with May Bartram, whose face, a reminder, yet not quite a remembrance, as they sat, much separated, at a very long table, had begun merely by troubling him rather pleasantly. (“The Beast in the Jungle,” in The Better Sort [Charles Scribner’s Sons, 1903], 190)

This sentence might be edited to conform to Chicago style as follows:

It led in short, in the course of the October afternoon, to his closer meeting with May Bartram, whose face, a reminder yet not quite a remembrance as they sat much separated at a very long table, had begun merely by troubling him rather pleasantly.

James famously dictated his writing by that point in his career; one can imagine him pausing over each successive layer of meaning as he spoke the words aloud. But when the goal is primarily to make sure readers understand the text rather than to provide a record of the creative process, all those extra commas can get in the way.

So unless you’re dealing with an accomplished prose stylist, you might say to your recalcitrant authors that whereas at least some of their readers will be annoyed by superfluous or random commas, few if any will miss them when they’re gone. For another take on this subject, see “Sure, You Got A’s in English—But Do You Know Where Commas Go?” at CMOS Shop Talk.

A. When a pair of correlative conjunctions like not . . . but, either . . . or, or both . . . and joins two independent clauses, the clauses should be separated by a comma unless they are very short and closely related. In other words, the rule about independent clauses takes precedence (see CMOS 6.22).

This situation arises when the subject of the first clause follows rather than precedes the opening conjunction. In that case, another subject (often the same one) is required after the coordinating conjunction, which is then preceded by a comma:

Not only did we camp in the woods, but we also canoed down the river.

Either we will camp in the woods, or we will canoe down the river.

Compare the same sentences but with the subject moved to precede the opening conjunction:

We not only camped in the woods but also canoed down the river.

We will either camp in the woods or canoe down the river.

In that case, the subject isn’t repeated, so no comma is needed (see CMOS 6.23 and 6.46). For more information about correlative conjunctions, see CMOS 5.199 and 5.244.

A. Your author’s style seems fine to us. The word that—whether as a relative pronoun or, as in your examples, as a subordinating conjunction—is often omitted. Relative pronoun: “The room [that] I entered was shadowy.” Subordinating conjunction: “I was so hungry [that] I nearly fainted.”

In the first case, a comma in place of that would be clearly wrong; commas never set off a restrictive relative clause (called a contact clause when the relative pronoun is omitted). But a comma in the second example might add a bit of clarity, especially if the clauses were longer and you didn’t have the option of retaining that.

Nor would we necessarily consider your sentences as having comma splices; they’re more like compound sentences with elided conjunctions. If you’re consistent with your author’s prose and suggest rephrasing wherever clarity is at stake, her style will begin to seem natural, allowing the story to take center stage.

A. When “or” is used to introduce an equivalent rather than an alternative, a comma is strictly correct. Compare the following examples:

To get to the stadium, you can take a train or a bus.

To get to the stadium, you can take the elevated train, or el.

In the first example, “a bus” is an alternative to “a train”; it is not another way of writing “a train.” A comma is therefore unnecessary. In the second example, “el” is equivalent to “elevated train,” so the comma is correct. Still, such a comma may be omitted in certain cases, provided the meaning remains clear. You may want to do this, for example, to avoid comma clutter in text that mentions more than a few such equivalents. In an example like yours, which presents not two equivalent terms but three—all in a single sentence—the comma before “or” remains strictly correct. But it’s a little fussy and could be omitted if done so consistently.

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.

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.”

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.

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.