- Use a comma (,) after an adverbial dependent clause when the dependent clause precedes the main clause. When the dependent clause does not begin the sentence, the comma usually is unnecessary.
• Before you go to work, be sure to pack your lunch.
• Be sure to pack your lunch before you go to work. (no comma)
Use a comma after a participial phrase or an absolute phrase at the beginning of a sentence.
• Falling from the table top, the cat turned over and landed on all four feet. (participial phrase)
• His computer having crashed, Derek decided to take a break. (absolute phrase)
Use a comma after an introductory infinitive phrase, unless the infinitive phrase is the subject of the sentence.
• To comprehend a new language, one must study diligently.
• To become computer literate was important to Alexis. (no comma)
Use commas to set off “parenthetical” expressions, whether transitional words, phrases, clauses, or expressions, from the rest of the sentence.
- Transitional words such as however, therefore, moreover, besides, and consequently should be set off by commas. (The transitional word also generally is not set off by a comma, unless the writer wishes to emphasize it strongly.)
• Moreover, his boss gave him a bonus.
Phrases such as so to speak, in short, as a result, of course, and without a doubt should be set off by commas.
• Besides, she made a higher salary than her husband.
• Also, they decided to liquidate most of their stocks.
• Bill also entered the triathlon competition. (no comma)
• As a result, his employment with the firm was terminated.
Clauses such as I believe, we suppose, he says, and she felt should be set off by commas.
• The attorney felt, without a doubt, that her client was innocent of all charges.
• Rachel, I believe, deserves public recognition for her efforts.
Explanatory expressions such as and it seems feasible to me, so far as he is concerned, as much as is humanly possible, and for the life of me, which break the logical sequence of words, should be set off by commas.
• The President, she felt, should have been truthful from the beginning.
• Their plan, and it seems feasible to me, will be implemented tomorrow morning.
• I cannot, for the life of me, understand their unreasonable demands.
Use a comma after introductory words such as yes, indeed, surely (when it means yes), of course, and well.
• Indeed, she always responds to emails from friends.
• Surely, I intend to keep that commitment.
Use commas to set off a nonrestrictive clause, which is not essential to complete the meaning of a sentence. (A nonrestrictive clause is similar to a parenthetical expression in that it gives added, nonessential information about the word or group of words it modifies.) Do not use commas to set off a restrictive clause, which is necessary to complete the meaning of the sentence. (A nonrestrictive clause can be omitted from a sentence; whereas, a restrictive clause cannot be omitted from a sentence.)
• Kevin Suazo, who saved those kids from the burning house, will receive a hero’s celebration in the plaza tomorrow. (a nonrestrictive clause giving added, nonessential information about “Kevin Suazo”: commas used)
• The guy who saved those kids from the burning house will receive a hero’s celebration in the plaza tomorrow. (a restrictive clause identifying “guy”: no commas used)
Use commas to set off an appositive, which is a word or phrase that defines or identifies another word or group of words.
• Mr. Gomez, the mayor, will run for re-election.
• His cardiologist, Dr. Cohen, gave him a clean bill of health.
- Most of the time, an appositive at the end of a sentence should be preceded by a comma.
• The annual meeting will be in San Diego, a major convention city.
A very closely related appositive does not require a comma or commas to set it off.
• My Uncle Bill will arrive tomorrow.
• The gift was from her friend Giselle.
• Henry the Eighth had many wives.
• The novel’s main character was Catherine the Great.
Use commas to set off words in a direct address.
• You will be happy to learn, Ms. Jackson, that you have won the drawing.
• Kathy, let me use your computer to check my email.
Use a comma to separate a series of three or more words, phrases, or clauses.
• The lunch menu at the senior center included green chile stew, tossed salad, cornbread, and ice cream.
• She backed out into the street, remembered she had forgotten her purse, and pulled back into the driveway.
• During the monthly church meeting, those in attendance voted (1) to increase their city-wide outreach, (2) to place an order for new choir robes, and (3) to break ground on a new church building.
- To avoid confusion, it is safe to place a comma before the conjunction joining the last two members of a series (although this comma generally is considered to be optional).
• On the menu, the ingredients of the burrito selection were listed as “beans, roast beef or ground beef, and cheese.” (Without the final comma, the ingredients could be misconstrued as being “beans,” “roast beef,” or “ground beef and cheese.”)
Do not use a comma before a conjunction joining words of a series that are considered to be unit.
• Dancers and football, baseball, and tennis players are vulnerable to Achilles tendonitis. (Without the final comma, those affected by Achilles tendonitis could be misconstrued as being “dancers and football” and “baseball and tennis players.”)
• My least favorite entrées are cheesesteak, menudo, and liver and onions.
Use a comma to separate coordinate adjectives which modify the same noun. (Adjectives are “coordinate” if the word and can be used between them.)
• She is the most beautiful, talented participant in the pageant. (could be written “beautiful and talented participant”: comma used)
• I found these ten gold coins in an old box upstairs. (could not be written “ten and gold coins”: no comma used)
Use a comma before a coordinate conjunction—such as and, but, or, nor, for, or while (when it means the same as but)—which joins the independent clauses of a compound sentence.
• Doug wanted to take a vacation, but he had too much work to do.
• Keep all of your commitments, or do not even make them.
• He enjoys playing tennis, while his wife would rather play golf.
- If the independent clauses of a compound sentence are very short and closely connected, the comma may be omitted.
• Monica listened but she heard nothing.
Do not use a comma between two independent clauses unless a coordinate conjunction is included. A comma used without a coordinate conjunction is referred to as a “comma splice.”
• The President is the most important national figure, he should exemplify the utmost in honesty and integrity. (incorrectly used comma; “comma splice”)
The previous comma fault can be eliminated any of the following three ways:
• The President is the most important national figure, and he should exemplify the utmost in integrity. (inclusion of a coordinate conjunction between the two independent clauses)
• The President is the most important national figure; he should exemplify the utmost in integrity. (use of a semicolon rather than a comma)
• The President is the most important national figure. He should exemplify the utmost in integrity. (two simple sentences)
Use a comma to set off words or phrases expressing contrast.
• The Bible account of creation supports science, not refutes it.
• Lucy always wanted a lucrative position, but never with so many responsibilities attached.
Use a comma to separate the month and day from the year. Another comma after the year is optional. If the date is used as an adjective, it is permissible to omit the comma after the year. Do not use commas if any part of the date is omitted, or if a date is written in day/month/year form.
• The tax cut was made retroactive to January 1, 2001, by a majority vote of Congress and approval by the President. (comma after 2001 is optional)
• The September 11, 2001 attacks on New York and Washington, DC, permanently changed airline security regulations in the United States. (permissible not to use a comma after 2001, since “September 11, 2001” is used as an adjective modifying “attacks”)
• They had met in December 1999 at a Y2K discussion group. (no comma)
• Mike wrote in his daily log that 30 June 2000 was the beginning of his attitude change. (no comma)
Use a comma to separate the elements of a location, followed by another comma.
• The family drove from Washington, D.C., to Ottawa, Canada, in two days.
• Juliette lived at 846 Oak Lane, Houston, Texas, until she was married.
Use a comma to set off a direct quotation.
• She reluctantly admitted, “I made the muffins from a generic store-bought mix.”
• The baseball coach exclaimed, “Get that ball and throw it!”
Use a comma to substitute for an exclamation mark after a mild interjection.
• Well, I hope you’re satisfied.
• Hey, did you hear that?
Use a comma after inverted names in lists.
• Lincoln, Abraham
• Fillmore, Martha Billings
Use a comma to indicate the omission of a word or words.
• The wage of hard work is prosperity; of laziness, poverty; and of sin, death.
• According to the rules, the winner will receive $500; the first runner up, $300; and the second runner up, $150.
Use a comma to set off a proper name when followed by an academic degree or honorary title. The comma is used to separate two or more degrees or titles.
• James H. Sterling, Ph.D., M.D., fellow of ophthalmology
• Susan Briggs, valedictorian, student body president, varsity softball captain
- A colon may be used instead of the first comma:
• James H. Sterling: Ph.D., M.D., fellow of ophthalmology
• Susan Briggs: valedictorian, student body president, varsity softball captain
Use a comma to group the digits in thousands in figures of four digits or more.
- Do not use a comma in years or in phone, page, address, and policy numbers.
|• Year 1954
||• Zenith 5-8149
||• Page 1059
|• 16372 East Elm Street
||• Policy No. 384670
Use a comma to separate two identical words or two sets of figures.
• Curtis had lost it, it seemed.
• We told you, you might regret doing that.
• Buy me 20, 41¢ stamps and 10, 65¢ stamps.
• By 2000, 281,421,906 people were estimated to reside in the United States, with the most populous states being California, Texas, and New York.
Use a comma to separate a declarative clause from an interrogative clause which immediately follows.
• Your speech is a little wordy, is it not?
• Mia wrote the best story, don’t you think?
Use the comma to separate a phrase from the rest of the sentence when the phrase is inverted or out of its natural order.
• Per Wendy, the biggest news was that they had won the game.
• For him, the layoff could not have come at a worse time.
• No matter what he says, Loren will be there.
Copyright © 1998– by Ted M. Montgomery. All rights reserved.