English Grammar for the Utterly Confused - Laurie Rozakis 2003
Commas
Chapter 10 Punctuation
Part 4 A Writers Tools
Commas are the most frequently used marks of punctuation in English. In fact, commas occur in writing twice as often as all other marks of punctuation combined!
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.
Here’s the overall comma alert:
As you write, don’t add commas just because you paused in your reading. Since everyone pauses at different times, a pause isn’t a reliable way to judge comma use. Instead, rely on the rules that govern comma use.
And here are those guidelines:
1. 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.
The movie was sold out, so we decided to have an early dinner.
The movie was a blockbuster, but we arrived early enough to get seats.
Our friends are easy-going, and they don’t get upset when plans change.
• Use a comma to set off dialogue.
Martha said, “This movie won an Academy Award.”
“This movie,” Martha said, “won an Academy Award.”
“This movie won an Academy Award,” Martha said.
• Use a comma to separate the parts of an address. Do not use a comma before the zip code in an address.
Rick lives at 163 East Plains Drive, Boston, MA 89012
2. Use a comma after introductory and concluding expressions.
• Use a comma after an introductory word.
Yes, I will be coming to the retirement party.
However, I won’t be able to bring a macaroni salad.
• Use a comma after an introductory phrase.
To get a good night’s sleep, you should practice relaxation techniques.
Beginning tomorrow, the store will be open until midnight.
• Use a comma after an introductory clause.
Although the sky is overcast, I don’t think that it will rain this afternoon.
Since you can’t do the dishes, could you please walk the dog tonight?
• Use a comma after the greeting of an informal letter.
Dear Mom,
Dear Mickey,
• Use a comma at the close of any letter.
Yours truly,
Sincerely,
3. Use a comma after interrupting words and expressions.
• Use a comma to set off interrupting words and expressions.
The State University of New York, did you know, has 64 campuses scattered across New York State.
• Use a comma to set off words of direct address (words that tell to whom a remark is addressed).
Nanci, please clean up your room.
Please clean up your room, Nanci.
• Use a comma with names and titles.
Ms. Barbara Gilson, Editorial Director
Laurie Rozakis, Ph.D.
• Use a comma to set off words in apposition (words that give additional information about the preceding or following word or expression).
A good eater, my baby will be off the bottle soon.
My baby, a good eater, will be off the bottle soon.
• Use a comma to set off a nonessential clause (a clause that can be omitted without changing the sentence’s basic meaning).
Elizabeth II, who was born in 1926 in London, is the queen of England.
Prince Charles, Elizabeth’s first child, was born in 1948.
• Use a comma to separate items in a series. The comma before and in a series of items is optional.
The store had a sale on hot dogs, watermelon, and paper plates.
Quick Tip
Never use commas to set off an essential clause, a clause that cannot be omitted.
Some states retest drivers who are over age 65 to check their ability to drive safely.
4. Use commas to prevent misreading.
• Use a comma to clarify any potentially confusing sentences.
Confusing: Those who can practice many hours every day.
Clear: Those who can, practice many hours every day.
Rewritten: Those who can practice, do so many hours every day.
Confusing: Luisa dressed and sang for an enthusiastic crowd.
Clear: Luisa dressed, and sang for an enthusiastic crowd.
Rewritten: After Luisa dressed, she sang for an enthusiastic crowd.
Of course, as the rewritten examples show, you’re usually much better off revising the sentences so there is no possibility of your audience misreading your words.
5. Use commas with numbers. Do not use commas when writing telephone numbers, page numbers, or years.
• Use a comma between the day of the month and the year.
December 7, 1941 July 20, 1969
• Use commas to show thousands, millions, and so on.
5,000
50,000
500,000
5,000,000