Rules for Using Rules for Using CommasCommas

The comma is a valuable, useful The comma is a valuable, useful punctuation device because it punctuation device because it

separates the structural elements of separates the structural elements of sentences into manageable segments.sentences into manageable segments.

1. Use commas to separate independent 1. Use commas to separate independent clauses when they are joined by clauses when they are joined by and, but, and, but,

for, or, nor, so, yet.for, or, nor, so, yet.

The game was overThe game was over, but, but the crowd refused the crowd refused to leave.to leave.

The student explained her questionThe student explained her question, yet, yet the the instructor still didn't seem to understand.instructor still didn't seem to understand.

2. Use commas after introductory 2. Use commas after introductory a) clauses, b) phrases, or c) words that a) clauses, b) phrases, or c) words that

come before the main clause.come before the main clause.

A. Common starter words for introductory clauses that A. Common starter words for introductory clauses that should be followed by a comma include should be followed by a comma include afterafter, , althoughalthough, , asas, , becausebecause, , ifif, , sincesince, , whenwhen, , whilewhile. .

While I was eatingI was eating,, the cat scratched at the door. the cat scratched at the door. BecauseBecause her alarm clock was broken her alarm clock was broken,, she was late for she was late for

class. class.

However, don't put a comma after the main clause when a However, don't put a comma after the main clause when a dependent clause follows it.dependent clause follows it.

She was late for class, because her alarm clock was She was late for class, because her alarm clock was broken. (incorrect) broken. (incorrect)

Rule #2 continuedRule #2 continued

b. Common introductory phrases b. Common introductory phrases

Having finished the test, he left the room.Having finished the test, he left the room.To get a seat, you'd better come early.To get a seat, you'd better come early.

c. Common introductory words that should be c. Common introductory words that should be followed by a comma include followed by a comma include yesyes, , howeverhowever, , wellwell..

Well,Well, perhaps he meant no harm. perhaps he meant no harm.Yes,Yes, the package should arrive tomorrow the package should arrive tomorrow morning. morning.

3. Use a pair of commas in the middle of 3. Use a pair of commas in the middle of a sentence to set off clauses, phrases, a sentence to set off clauses, phrases, and words that are not essential to the and words that are not essential to the

meaning of the sentence.meaning of the sentence.

Clause:Clause: That Tuesday, That Tuesday, which happens to be my which happens to be my birthdaybirthday, is the only day when I am available to , is the only day when I am available to meet.meet.

Phrase:Phrase: This restaurant has an exciting This restaurant has an exciting atmosphere. The food, atmosphere. The food, on the other handon the other hand, is , is rather bland.rather bland.

Word:Word: I appreciate your hard work. In this case, I appreciate your hard work. In this case, howeverhowever, you seem to have over-exerted , you seem to have over-exerted yourself.yourself.

4. DO NOT use commas to set off 4. DO NOT use commas to set off essential elements of the sentence, such essential elements of the sentence, such

as clauses beginning with as clauses beginning with thatthat.. The book The book that I borrowed from youthat I borrowed from you is excellent. is excellent.The apples The apples that fell out of the basketthat fell out of the basket are bruised. are bruised.

Examples of other Examples of other essentialessential elements (no commas): elements (no commas): Students Students who cheatwho cheat only harm themselves. only harm themselves.

The baby The baby wearing a yellow jumpsuitwearing a yellow jumpsuit is my niece. is my niece.

4a. DO use commas to set off nonessential 4a. DO use commas to set off nonessential elements:elements:

Fred, Fred, who often cheatswho often cheats, is just harming himself., is just harming himself.

My niece, My niece, wearing a yellow jumpsuitwearing a yellow jumpsuit, is playing in the living , is playing in the living room. room.

5. Use commas to separate three or more 5. Use commas to separate three or more words, phrases, or clauses written in a words, phrases, or clauses written in a

series.series.

The Constitution establishes the legislative, The Constitution establishes the legislative, executive, and judicial branches of executive, and judicial branches of government.government.

The candidate promised to lower taxes, The candidate promised to lower taxes, protect the environment, reduce crime, protect the environment, reduce crime, and end unemployment.and end unemployment.

6. Use commas to separate two or more 6. Use commas to separate two or more coordinate adjectives that describe the coordinate adjectives that describe the

same noun.same noun. Coordinate adjectivesCoordinate adjectives – –adjectives with equaladjectives with equal ("co"-ordinate) ("co"-ordinate) status in status in

describing the noundescribing the noun

He was a difficult, stubborn child. He was a difficult, stubborn child. (coordinate)(coordinate)

They lived in a white frame house. They lived in a white frame house. (non-coordinate) (non-coordinate)

7. Use a comma near the end of a sentence 7. Use a comma near the end of a sentence to separate contrasted coordinate to separate contrasted coordinate

elements or to indicate a distinct pause or elements or to indicate a distinct pause or shift.shift.

He was merely ignorant, not stupid.He was merely ignorant, not stupid.

The chimpanzee seemed reflective, almost The chimpanzee seemed reflective, almost human.human.

8. Use commas to set off phrases at the 8. Use commas to set off phrases at the end of the sentence that refer back to the end of the sentence that refer back to the

beginning or middle of the sentence.beginning or middle of the sentence.

Nancy waved enthusiastically at the docking Nancy waved enthusiastically at the docking shipship,, laughing joyously. laughing joyously.

Laughing joyouslyLaughing joyously,, Lisa waved at Nancy. Lisa waved at Nancy.

9. Use commas to set off all geographical 9. Use commas to set off all geographical names, items in dates (except the month names, items in dates (except the month

and day), addresses (except the street and day), addresses (except the street number and name), and titles in names.number and name), and titles in names.

Birmingham, Alabama, gets its name from Birmingham, Alabama, gets its name from Birmingham, England.Birmingham, England.

July 22, 1959, was a momentous day in his July 22, 1959, was a momentous day in his life.life.

10. Use a comma to shift between the 10. Use a comma to shift between the main discourse and a quotation.main discourse and a quotation.

John said without emotion, "I'll see you John said without emotion, "I'll see you tomorrow."tomorrow."

"I was able," she answered, "to complete the "I was able," she answered, "to complete the assignment."assignment."

11. Use commas wherever necessary to 11. Use commas wherever necessary to prevent possible confusion or prevent possible confusion or

misreading.misreading.

To George, Harrison had been a sort of idol.To George, Harrison had been a sort of idol.