Few punctuation marks are misused as often as the comma. Sadly, many semi-professional or hobby writers of today seem to think that the comma is meant to signify vocal pauses. But, like any punctuation, the comma has specific uses: none of them involve noting vocal pauses.

In The Editorial Eye Vol. 25, No. 11, I saw a comma usage aptitude test entitled, “Be Conservative but Canny with Comma Use.” As the title of the article implies, and as I've already mentioned, comma usage has skyrocketed recently and created something of a comma epidemic. So before the already overworked comma devolves into nothing more than a signal to the reader to take a breath, let’s review the rules of comma usage to ensure that this august punctuation mark retains its force.

To separate elements of a location or date. For example, “I work in Toronto, Ontario,” or, “Please send me your answer by March 9, 2017.”

As a mark that separates items in a list. For instance, “I had tea, a sandwich, and soup for lunch.” The only thing to keep in mind when using a comma in this manner is whether or not to use the serial, or Oxford, comma – as I have in my example. Without the use of the serial comma, the sentence would read, “I had tea, a sandwich and soup for lunch.”

To separate independent clauses that use coordinating conjunctions, i.e., for, and, nor, but, or, yet, and so. For example, “It’s time to go to the office, but I forgot my bus fare.”

To set off parenthetical information. As the word “parenthetical” suggests, this information is not essential to the meaning of the sentence. For instance, “My dog, whose name is Rex, is a good companion.”

To separate introductory words or phrases. For example, “Well, that’s a great idea.”

To separate two or more coordinate adjectives. For instance, “The big, old house on the hill was beautiful.”

To set off free modifiers, i.e., phrases that modify an element previously mentioned in the sentence. For instance, “Jimmy ate dinner, gagging all the while.” “Gagging all the while” is a free modifier because it can be moved to any other part of the sentence and still make sense, e.g., “Gagging all the while, Jimmy ate dinner.”

To signify a shift from a piece of writing’s main text to a quotation within it. For instance, “Jimmy interrupted by saying, ‘Where’s the beef?’”

To set off information in a sentence that indicates a shift from the previous text, and to separate contrasted coordinate elements. For instance, “I’m not going to the movies, did you hear me?” This comma may seem like it’s standing in for a vocal pause, but it isn’t.

To avoid confusion or misreading. This last rule is open to some interpretation but not much. For example, in “He was eating apples, and oranges,” though the comma precedes a coordinating conjunction, the comma is incorrect because the word “oranges” isn’t an independent clause. Instead, this rule is correctly applied as follows in this example, “For George, Washington was the best place in the world.”

And that’s more or less it. If you’re not using a comma for any of the above reasons then you may be using it incorrectly. So, having reviewed the rules, try your hand at The Editorial Eye’s test. Can you correct the incorrect sentences and pick the single correct one out from among the others?

1. Tarot cards, which date back to 15th-century Italy, were used by the Renaissance elite to play parlor games, and found new popularity in the Victorian era.

2. “River Song” and “Woza” (Zulu for “come”) wisely caught the essence of very different dance styles without imitating their forms.

3. Authoritarian governments restrict public debate and tradition-bound religious establishments, allied to the state, reject new interpretations of Islamic scriptures.

4. One of those research programs is devoted to biodefense, the other to the burgeoning discipline of bioinformatics, which combines biology and information technology.

Answers:

1. Tarot cards, which date back to 15th-century Italy, were used by the Renaissance elite to play parlor games and found new popularity in the Victorian era. [Remove comma after games]

2. Correct.

3. Authoritarian governments restrict public debate, and tradition-bound religious establishments, allied to the state, reject new interpretations of Islamic scriptures. [Add comma after debate. Without the first comma, the sentence loses its meaning. And, as The Editorial Eye points out, without the commas, “allied … state” becomes restrictive.]

4. One of those research programs is devoted to biodefense and the other to the burgeoning discipline of bioinformatics, which combines biology and information technology. [Remove comma after biodefense and insert “and”]

Thanks to The Editorial Eye for setting out these rules!