Commas
Mrs. Bowles
A comma is generally used to separate words or groups of words so that the meaning of a sentence is clear.
1. Items in a Series
RULE: Use commas to separate items in a series.
Words, phrases, and clauses in a series are usually separated by commas to show the reader where one item in the series ends and the next item begins.
Words in a Series ______
Barbecue, hammock, canoe, and moccasin are four of the words that the English language owes to American Indians. [nouns]
Always stop, look, and listen before crossing railroad tracks. [verbs]
In the early morning, the lake looked cold, gray, and calm. [adjective]
Phrases in a Series______
Checking his shoelaces, fastening his helmet strap, and positioning his kneepads, Toshio prepared for the skateboarding competition. [participial phrases]
We found seaweed in the water, on the sand, under the rocks, and even in our shoes. [prepositional phrases]
Clearing the table, washing the dishes, and putting everything away took almost an hour. [gerund phrases]
Clauses in a Series______
We didn’t know where we were going, how we would get there, or when we would arrive. [subordinate clause]
The lights dimmed, the curtain rose, and the orchestra began to play. [short independent clauses]
NOTE Independent clauses in a series can be separated by commas only if the clauses are short. Independent clauses that are long or that contain commas are usually separated by semicolons.
Notice how the commas affect the meaning in the following examples.
UNCLEAR Luanne, Zack and I are going riding. [Is Luanne being addressed, or is she going riding?]
CLEAR Luanne, Zack, and I are going riding. [Three people are going riding.]
If all the items in a series are joined by and, or, or nor, do not use commas to separate them.
EXAMPLES I voted for Corey and Mona and Ethan in the student council officer’s election.
For your report you may want to read Jean Tommer’s Cane or Ralph Ellison’s Invisible Man or Richard Wright’s Native Son.
2. Adjectives
RULE: Use commas to separate two or more adjectives preceding a noun.
EXAMPLES Jack Russell terriers are small, energetic dogs.
These intelligent, loyal, playful pets always enjoy a challenge.
When the final adjective in a series is thought of as part of the noun, do not use a comma before that adjective.
EXAMPLE: A skillful, enthusiastic dog trainer can teach a Jack Russell to perform many exciting tricks. [No comma is used between enthusiastic and dog because the words dog and trainer make up a compound noun.]
A comma should never be used between an adjective and the noun immediately following it.
INCORRECT The cute, clever, terrier who stars in TV’s Wishbone is really named Soccer.
CORRECT The cute, clever terrier who stars in TV’s Wishbone is really named Soccer.
3. Compound Sentences
RULE: Use a comma before a coordinating conjunction (for, and, nor, but, or, yet, so) {fanboys} when it joins independent clauses in a compound sentence.
EXAMPLES I enjoyed The King and I, but Oklahoma! is still my favorite musical.
Oscar Hammerstein wrote the words, and Richard Rodgers wrote the music.
The musical comedy began as an American musical form, yet its popularity has spread throughout the world.
When the independent clauses are very short, the comma before and, but, or or is sometimes omitted.
EXAMPLES I’m tired but I can’t sleep.
The cat can stay inside or it can go out.
A comma is almost always used before nor, for, so, or yet when it joins independent clauses.
EXAMPLES We will not give up, nor will we fail.
Everyone seemed excited, for it was time to begin.
No one else was there, so we left.
The water was cold, yet it looked inviting.
NOTE : Do not confuse a compound sentence with a simple sentence that has a compound verb. A simple sentence has only one independent clause.
SIMPLE SENTENCE WITH Margo likes golf but doesn’t enjoy archery.
COMPOUND VERB
COMPOUND SENTENCE Margo likes golf, but she doesn’t enjoy archery. [two independent clauses]
NOTE: When the independent clauses in a compound sentence contain commas, a semicolon may be
needed before the coordinating conjunction.
EXAMPLE: Our class will read Chapter 4, Chapter 7, and Chapter 9; and Larry, Dana and Barath will
present reports on them.
4. Interrupters
RULE: Use commas to set off an expression that interrupts a sentence.
Two commas are used to set off an interrupting expression – one before and one after the expression.
EXAMPLES: Mr. Agoya, born and raised in Mexico, moved to California at the age of twenty-four.
The applications, by the way, were mailed three days ago.
Some expressions that are used as interrupters can also come at the beginning or the end of a sentence. In such cases, only one comma is needed.
EXAMPLES Born and raised in Mexico, Mr. Agoya moved to California at the age of twenty-four.
The applications were mailed three days ago, by the way.
5. Nonessential Phrases and Clauses
RULE: Use commas to set off nonessential participial phrases and nonessential subordinate
clauses.
A nonessential (or nonrestrictive) phrase or clause adds information that is not needed to understand the basic meaning of the sentence. Such a phrase or clause can be omitted without changing the main idea of the sentence.
NONESSENTIAL
PHRASES This small turtle, crossing the street slowly, was in danger. [The main idea of the sentence remains This small turtle was in danger.]
Harvard College, founded in 1636, is the oldest college in the United States. [The main idea of the sentence remains Harvard College is the oldest college in the United States.]
NONESSENTIAL
CLAUSES Kareem Abdul-Jabbar, who retired from professional basketball, holds several NBA records. [The main idea of the sentence remains Kareem Abdul-Jabbar holds several NBA records.]
Joshua eventually overcame his acrophobia, which is the abnormal fear of being in high places. [The main idea of the sentence remains Joshua eventually overcame his acrophobia.]
Do not use commas to set off an essential (or restrictive) phrase or clause. Since such a phrase or clause tells which one(s), it cannot be omitted without changing the meaning of the sentence.
ESSENTIAL
PHRASES All farmers growing the new hybrid corn should have a good harvest. [Without the essential phrase, the sentence says All farmers should have a good harvest.]
The theories developed by Einstein have changed the way people think about the universe. [Without the essential phrase, the sentence says The theories have changed the way people think about the universe.]
ESSENTIAL
CLAUSES The map that we were using did not show your street. [Without the essential clause, the sentence says The map did not show your street.]
Often, someone who does a good deed gains more that the person for whom the deed is done. [Without the essential clauses, the sentence says Often someone gains more that the person.]
6. Nonessential Appositives and Phrases
RULE: Use commas to set off nonessential appositives and nonessential appositive phrases.
A nonessential appositive or appositive phrase provides information that is unnecessary to the meaning of the sentence.
EXAMPLES My best friend, Nancy, is studying ballet.
We’re out of our most popular flavor, vanilla.
Sara, my cousin, has won a dance scholarship.
The Rio Grande, one of the major rivers of North America, forms the border between Texas and Mexico.
An essential appositive adds information that makes the noun or pronoun it identifies more specific. Do not set off an essential appositive.
EXAMPLE The blues singer Bessie Smith wrote the song “Backwater Blues.” [The appositive Bessie Smith tells which blues singer. The appositive “Backwater Blues” tell which song.]
7. Direct Address
RULE: Use commas to set off words of direct address.
EXAMPLES Mrs. Clarkson, this package is addressed to you.
Do you know, Odessa, when the next bus is due?
I’d like to go now, Jeff.
8. Parenthetical Expressions
RULE: Use commas to set off parenthetical expressions.
A parenthetical expression is a remark that adds information or shows a relationship between ideas.
EXAMPLES The president said, of course, that he was deeply disappointed.
In my opinion, the movie was too violent.
Commonly Used Parenthetical Expressions
After all / Generally speaking / Of courseAt any rate / I believe (hope, suppose, think) / On the contrary
By the way / In my opinion / However
For instance / Nevertheless / Therefore
Some of the above expressions are not always used as interrupters. Use commas only when the expressions are parenthetical.
EXAMPLES Sidney, I think, volunteers at the senior center. [parenthetical]
I think Sidney volunteers at the senior center. [not parenthetical]
Traveling by boat may take longer, however. [parenthetical]
However you go, it will be a delightful trip. [not parenthetical]
9. Introductory Words, Phrases, and Clauses
RULE: Use a comma after certain introductory elements.
Introductory Words
Use a comma to set off a mild exclamation such as well, oh, or why at the beginning of a sentence. Other introductory words, such as yes and no, are also set off with commas.
EXAMPLE Well, I think we should ask for help.
Yes, I understand the problem.
Prepositional Phrases
A comma is used after an introductory prepositional phrase if the phrase contains two or more prepositions or five or more words.
EXAMPLES In the darkening attic room, the girls searched for the box of old photos.
At night in the desert, the temperature falls rapidly.
Verbal Phrases
A comma is used after a participial phrase or an infinitive phrase that introduces a sentence.
PARTICIPIAL PHRASE Signaling the referee for a timeout, the coach gathered her players for a pep talk.
INFINITIVE PHRASE To keep your bones strong, be sure to get regular exercise and eat foods rich in calcium.
NOTE: Sometimes an infinitive phrase at the beginning of a sentence is the subject of the sentence. In
such a case, the infinitive should not be followed by a comma.
EXAMPLE To become a museum curator is Shanda’s dream.
Adverb Clauses
An adverb clause may be placed at various places in a sentence. When it begins a sentence, the adverb clause is followed by a comma.
EXAMPLES When March came, the huge ice floe began to melt and break up.
Because I had a sore throat, I could not audition for the school play.
10: Conventional Situations
RULE: Use commas in certain conventional situations, and use commas to separate items in dates and addresses.
EXAMPLES:
The United States officially observed Martin Luther King Jr., Day for the first time on January 20, 1986.
Each year the Kentucky Derby is held in Louisville, Kentucky, on the first Saturday in May.