Comma Sense

By Jennifer Rappaport

Many usage guides provide guidance on when to use commas and when to omit them. Some commas are needed to prevent misreading, some are harmful, and others are optional. Since the mid–twentieth century, usage experts, such as Theodore M. Bernstein, have advocated using “a minimum of commas” (359). Claire Kehrwald Cook warns, “Commas call attention to words. They make readers pause and take notice. Unless you want that effect, don’t use commas that the sentence structure doesn’t require” (125). In other words, use commas only when they help make your meaning clear.

So when does a sentence have too many commas, and when does it have too few? Take the following example:

What time are we eating mother?

If mother is on the menu, then this sentence requires no commas. If, however, the question is addressed to mother, then a comma should be added before “mother”:

What time are we eating, mother?

Here’s another example:

This evening, the moon came out, and, as usual, the owls hooted.

You could include all these commas, but they might distract your reader. Since any of the commas could be omitted without changing the meaning of the sentence, you might pare down the punctuation in any one of a number of ways, depending on what you wish to emphasize:

This evening the moon came out, and as usual the owls hooted.
This evening, the moon came out and as usual the owls hooted.
This evening the moon came out, and, as usual, the owls hooted.

When the absence of commas might cause misreading, it is best to revise. The following sentence contains several necessary commas:

This evening the moon came out, but, as I explained later, I didn’t hear the owls hooting, because I went to bed before they appeared.

The first comma is necessary to separate two long independent clauses joined by but, the next two are needed to set off the inessential clause as I explained later, and the last comma is needed to make clear that the reason the speaker didn’t hear the owls hooting was because the speaker went to bed before they appeared and not, say, because the speaker was wearing earplugs.

To pare down the commas, you might revise as follows:

This evening the moon came out, but—as I explained later—I didn’t hear the owls hooting, because I went to bed before they appeared.
This evening the moon came out. As I explained later, I didn’t hear the owls hooting, because I went to bed before they appeared.

When it comes to commas, usage guides can help you with the rules, but ultimately you should use comma sense.

Works Cited

Bernstein, Theodore M. The Careful Writer: A Modern Guide to English Usage. Atheneum, 1965.

Cook, Claire Kehrwald. Line by Line: How to Edit Your Own Writing. Houghton Mifflin, 1985.

Published 24 March 2017

2 comments on “Comma Sense”

  1. Your suggested revision retains the final comma: “. . . I didn’t hear the owls hooting, because I went to bed before they appeared.” However, my understanding is that a comma is rarely, if ever, needed preceding a subordinating conjunction that introduces a dependent clause.
    In this case, I don’t find your justification for keeping the comma very convincing: “. . . the last comma is needed to make clear that the reason the speaker didn’t hear the owls hooting was because the speaker went to bed before they appeared and not, say, because the speaker was wearing earplugs.” Since the “reason” directly follows “because,” I don’t see any danger that the reader would misidentify or speculate about the cause (earplugs?). In my reading of the sentence, the final comma is nothing but an obstacle impeding the flow of information.

    • Great comment! My explanation could use some clarification, so here it is:

      I was following Claire Cook’s Line by Line (116) and Amy Einsohn’s The Copyeditor’s Handbook (84).

      Einsohn explains that when a negative independent clause precedes a because clause, a comma is used before because when the because clause is nonrestrictive—that is, nonessential to the meaning of the sentence. A comma is omitted when the because clause is restrictive. She provides the following examples:

      The proposal was not sent to New York, because the meeting had been postponed.

      The proposal was not sent to New York because of the impending merger.

      Regarding the first sentence, Einsohn explains, “The proposal was not sent, and the reason it was not sent was that the meeting was postponed.”

      Regarding the second sentence, she says, “The proposal was sent, but the impending merger was not the reason it was sent.”

      She adds, though, that it would be better to revise the second sentence for clarity:

      The proposal was sent to New York, but not because of the impending merger.

      Cook provides this example:

      We did not lose the contract because of our references from former employees.

      She says that if a comma is added before because, the sentence means that our references prevented us from losing the contract. Without the comma, the sentence likely means that we did lose the contract but not because of our references from former employers. She suggests revising for clarity as follows:

      It was not because of our references from former employers that we lost the contract.

      So in my owls example, the comma indicates: I didn’t hear the owls hooting, and the reason I didn’t hear them was because I went to bed before they appeared.

      Without the comma, the sentence means: I didn’t hear the owls hooting, but my going to bed before they appeared was not the reason I didn’t hear them.

      But instead of simply omitting the comma, it might be better to rewrite as follows:

      This evening the moon came out. But, as I explained later, it wasn’t because I went to bed before the owls appeared that I failed to hear them hooting. It was because I was wearing earplugs.

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