Punctuation: The Comma: A Major Player

The Comma: A Major Player

Punctuation helps readers identify clusters of words between and within sentences. Between sentences, the most common mark of punctuation is the period; within sentences, the most common mark is the comma.

Commas tell us how to read and understand sentences because they tell us where to pause. A correctly placed comma helps move readers from the beginning of a sentence to the end. A misplaced comma can create more confusion than a conversation with a teenager.

Here are the guidelines that govern comma use.

First Impressions Count

Use a comma after introductory and concluding expressions:

• Use a comma after an introductory prepositional phrase. In each sentence, the introductory phrase is underlined.

• Example: Along the route from the house to the woods, Hansel and Gretel left a trail of old lottery tickets.

• Use a comma after an introductory participial phrase.

• Example: Excited by their approach, the witch called her agent and decided to take a meeting.

• Use a comma after an introductory subordinate clause.

• Example: When Hansel and Gretel arrived, they were astonished to find the TV contract already prepared.

• Use a comma after the greeting of an informal letter.

• Examples: Dear Sammi, Dear Mudface,

• Use a comma after phrases that show contrast.

• Example: The neighbors return home at all hours, often drunk as skunks.

• Use a comma at the close of any letter.

• Examples: Yours truly, Sincerely, Yours until Niagara falls,

Sentence Interruptus

Use a comma after interrupting words and expressions.

• Use a comma to set off interrupting words and expressions. The interrupting words are underlined in the following example.

• Example: Windows, as you know, is the best $89 solitaire game you can buy.

• Use a comma to set off words of direct address (words that tell to whom a remark is addressed). The words in direct address are underlined in the following example.

• Example: Mr. Happy, did you know that “kitty litter” is throwing cats out a car window?

• Use a comma with names and titles.

• Example: Mr. Gary Goldstein, Editor

• Use a comma to set off words in apposition (words that give additional information about the preceding or following word or expression). The words in apposition are underlined in the following examples.

• Example: A light sleeper, my landlord is the first to awake when he hears the chains rattle.
• Example: My landlord, a light sleeper, is the first to awake when he hears the chains rattle.

• Use a comma to set off a nonessential clause (a clause that can be omitted without changing the sentence's basic meaning). The nonessential clause in underlined in the following example.

• Example: Philosophy, a science that lets us be unhappy more intelligently, is being offered this semester at the local university.

• Use a comma to separate items in a series.

• Example: We bought marshmallows, graham crackers, and chocolate to make those delicious campfire treats.

In Media Res

Use a comma to set off parts of a sentence:

• Use a comma to separate parts of a compound sentence. Use the comma before the coordinating conjunction. Remember: The coordinating conjunctions are and, but, or, nor, for, so, and yet. The coordinating conjunction is underlined in the following example.

• Example: The faucet stopped working, and the sink leaks.

• Use a comma to set off a direct quotation.

• Example: He said, “Lawyers are the larval form of politicians.”
• Example: “Lawyers,” he said, “are the larval form of politicians.”

• Use a comma to separate the parts of an address.

• Example: She lives at 763 Main Street, Farmingdale, New York 11735.

Dazed and Confused

Use commas to prevent misreading:

• Use a comma to clarify any potentially confusing sentences.

• Huh: To get through a tunnel must be dug.
• Revised: To get through, a tunnel must be dug.

Of course, you're usually much better off just revising the sentences so there is no possibility of a chowderhead misreading your words.

Bean Counters

Use commas with numbers:

• Use a comma between the day of the month and the year.

• Examples: December 7, 1941, July 20, 1969

• Use commas to show thousands, millions, and so on.

• Examples: 1,000; 10,000; 100,000; 1,000,000

Constant Commas

Add commas as necessary in the following sentences.

Excerpted from The Complete Idiot's Guide to Grammar and Style © 2003 by Laurie E. Rozakis, Ph.D.. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.

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