Comma Punctuation

Rules and Examples


Punctuation marksIn this lesson, we are going to learn the rules of comma punctuation ( , ) in the English language.

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Commas are used in many ways when writing in English.

The following rules will help you begin to use commas correctly when writing in English.

1. When listing items in a sentence, use comma punctuation to separate words or phrases of three or more.

Note: most American non-journalistic writers use a comma to separate the final item in the series, but some do not.

It can be a style matter. But whatever style you choose, make sure you are consistent!

Option B is more common and sometimes clearer to the reader.

Option A: The colors in my bedroom are blue, green and yellow.
Option B: The colors in my bedroom are blue, green, and yellow.

Option A: On our farm we have three cats, two goats, one cow and a pig.
Option B: On our farm we have three cats, two goats, one cow, and a pig.

Option A: Flour, sugar, butter and milk are what you need to buy.
Option B: Flour, sugar, butter, and milk are what you need to buy.

Option A: My best friends are Richard, Nick, Beth and Lisa.
Option B: My best friends are Richard, Nick, Beth, and Lisa.

kids on Halloween

2. Use a comma to separate two adjectives if you can reverse the order of the adjectives or insert "and" between the adjectives.

An adjective is a describing word such as big, small, yellow and soft.

Examples:

  • He is a little, short man.

    We would use a comma here because we can say:
    The man is little and short.

    We can also reverse the order of the two adjectives in the sentence:
    He is a short, little man.

  • I have a small, white cat.

    We need a comma here because we can say:
    The cat is small and white.

    We can also reverse the order of the two adjectives in the sentence:
    I have a white, small cat.

  • It was a cold winter night.

    We do not need a comma here because we would not say:
    It was a cold and winter night or The night was cold and winter!

    It does not make sense to reverse the order of the words:
    It was a winter cold night.
  • We went to a fun summer party.

    We do not need a comma here because we would not say:
    We went to a fun
    and summer party or The party is fun and summer!

    It does not make sense to reverse the order of the words:
    We went to a summer fun party.

    boy in water

3. When we use an -ly adjective we insert a comma to separate it from other adjectives.

By "-ly word" we mean a word ending with -ly. For example: quickly, lovely.

Some of the words ending with -ly are adjectives, but most are not.

Some adjectives ending with -ly:
  • She is a lovely lady.
  • This is a smelly fish.
  • Today is a holy day.
  • He has a friendly smile.
  • This game is silly.
Some words which are not adjectives ending with -ly:
  • The cat left quickly.
  • Sharon explains clearly.
  • The kids jumped happily.
  • They exercise regularly.
  • Naturally, we all agreed. 
  • Oddly, he did not come.
To test whether a word ending with -ly is an adjective, try saying it alone with the noun. If it sounds correct, it is an adjective, and you need a comma.

Examples:
  • She has a lovely, black horse.

    Lovely horse sounds correct, so we need a comma.

  • We walked the dog for a friendly, elderly lady.

    Friendly lady and elderly lady sound correct, so we need a comma between them.

  • I like to read in a brightly lit room.

    In this sentence we do not need a comma because brightly is not an adjective. Brightly room does not make sense.

    girl reading

4. When writing a date in a sentence:

  • Use a comma to separate the day from the year.

  • Use a comma after the year to separate it from the rest of the sentence.

This rule only applies when the date is written in this format:

Month Day, Year

Examples:
  • He was born on March 17th, 1981.

  • School will begin August 25, 2013, at 8:15 a.m.


Do not use a comma if the day or year is left out.

Examples:
  • He was born in March 1981.

  • School will begin on August 25.

    school


5. When writing a location in a sentence, we use commas to separate the city from the state.

A) Use a comma after the state if you spell out the name of the state.

Examples:
  • I am traveling to Austin, Texas, to visit my sister.

  • She was born in San Diego, California, in 1980.

B) Do not use a comma after the state if you use the two letter abbreviated (shortened) version of the state.

Examples:
  • I am traveling to Austin, TX to visit my sister.

  • She was born in San Diego, CA in 1980.

C) Do not use any commas around the state when addressing an envelope to be mailed at the post office.

Example:
  • 2307 North Main Street
    Austin TX 97532


6. Use commas when you write a sentence that directly addresses someone.

This is called a direct address and is used in writing when one person speaks directly to another person by using their name or title.

Examples:
  • Yes, teacher, I will finish my work.

  • Will you, Bill, show me how to do the mathematics problem?

  • Do you like horses, Joe?

  • I was wondering, Mr. Jones, if you would like to come to my house next week.

  • No, mother, I did not pick up all my toys.

    boy playing with toys

7. We also use commas around degrees or titles with names.

Examples:
  • John Smith, M.D.
    (= Doctor of Medicine)

  • Sally Ford, Ph.D.
    (= Doctor of Philosophy)

Commas are no longer used with Jr. (Junior) or Sr. (Senior) or II, III, IV and so on.

Examples:
  • Dan Jones III

  • Fred Meeker Jr.

  • William Scott Sr.


8. Use a comma to set apart an introductory word such as Yes, No, Well, Finally, Then, and Now.

An introductory word is a word that is used to begin a sentence but has nothing in common with the rest of the sentence.

Examples:
  • Yes, I would love to go to the park today!

  • Well, I never thought I would see a tiger.

  • Now, it is time to start the movie.

  • Then, it will be time to wash the dishes.

  • Finally, I am finished with my homework!

  • No, she does not like lizards.

    lizard

9. Use a comma with an introductory phrase to set it apart from the main sentence.

Introductory phrases are not complete clauses and are used to introduce the main part of the sentence.

If the phrase is three words or less, the comma is optional.

Examples:
  • On December 25, many families will celebrate Christmas in America.

    Or

  • On December 25 many families will celebrate Christmas in America.

  • In about two weeks, I will finally be 18 years old.

  • To prepare for the competition, Tim surfed every day.

    boy surfing

10. Use a comma with a coordinating conjunction (for, and, nor, but, or, yet, so) to connect two independent clauses in a compound sentence.

An independent clause is a complete thought and complete sentence with a subject and a verb.

Independent Clause + , + 
Coordinating Conjunction + Independent Clause

Examples:
  • My little brother likes candy, so I bought him a lollipop.

  • The dog chased the cat, but the cat ran up a tree.

  • Sarah wants to go to the theater, and Sandy wants to go to the zoo.

  • She likes flowers, so he bought her a bouquet.

    bear with flowers

11. When writing a quote, we use commas to set apart the quotation.

Examples:
  • My mom said, "Be nice to your sister."

  • "Please take good care of yourself," said the doctor.

  • "You can vote for a president this Tuesday," the man instructed.

  • "John," my father asked, "could you please take the dog outside?"

    boy with dog

12. When writing a Tag Question, use a comma to separate the statement from the question.

Examples:
  • You like horses, don't you?

  • His name is Bill, isn't it?

  • This Sunday is your birthday, correct?

  • That is a clown, right?
clown

13. Use commas around a description of someone or something in a sentence that has already been identified.

Only use a comma if you can remove the description and not change the meaning of the sentence.

Examples:
  • Mr. Johnson, my math teacher, told us to study for the test tonight.

    This would be clear too: Mr. Johnson told us to study for the test tonight.

  • Mrs. James, the dentist, was at the grocery store.

    This would be clear too: Mrs. James was a the grocery store.

  • My green bike, which has a flat tire, is parked in the garage.

    This would be clear too: My green bike is parked in the garage.

  • The team that won the competition will receive a trophy.

    We do not need commas around the description in this sentence because we cannot take out the phrase that won the competition without changing the meaning of the sentence.

    The team will receive a trophy does not tell us which team is receiving the trophy. The original sentence says that only the winning team will receive a trophy.

  • The students who failed the test must stay after school.

    We do not need commas in this sentence because we cannot take out the phrase who failed the test without changing the meaning of the sentence.

    The students must stay after school would mean that ALL students must stay after school.

    students
noun or noun phrase that follows another noun or pronoun and explains it is called an appositive.

For example, in this sentence:
The students who failed the test must stay after school.

The underlined phrase is an appositive.

Click here to learn more about English Appositives.


14. When you have two contrasting (opposite) phrases, use a comma to separate the phrases.

Examples:
  • That ball is mine, not yours.

  • The puppy is cute, but messy.

  • I am very tired, but still awake.

  • The alligator is cute, but dangerous.
alligator

15. When writing letters, use a comma after the greeting of a friendly letter and the closing in all letters.

Examples of greetings:
  • Dear John,
  • Dearest Mother,
  • Dear Mr. and Mrs. Smith,
  • Greetings,
Examples of closings:
  • Sincerely,
  • Your loving children,
  • Your friend,
  • Yours truly,
  • With love,
  • Love,

    bird with letter

Comma punctuation – caution:

As you can see, there are many ways to use commas in the English language, and we have not listed them all.

The biggest problem with commas is overuse. Try not to use a comma unless you can find a specific rule telling you to do so.

One common error in comma punctuation is the comma splice. Click here to learn more about comma splices and how to correct them.

girl with pencil

These were the uses of comma punctuation. Now that you know them, it is time to practice! Read and do exercises.

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