When to Use a Comma (,) in English with Rules and Examples

Commas are essential punctuation marks that help clarify the meaning of a sentence by indicating pauses, separations, or list items. Here are some important comma rules to keep in mind:

Comma Rules

Separating items in a list

Use commas to separate three or more items in a list.
For example: “I need to buy apples, bananas, and oranges.”

Separating adjectives

Use a comma to separate two or more adjectives when the order of the adjectives can be switched without altering the meaning.
For example: “She had a large, black dog.”

Separating independent clauses

Use a comma before a coordinating conjunction (and, but, for, nor, or, so, yet) to join two independent clauses.
For example: “She ran fast, but she did not win the race.”

Introducing direct quotations

Use a comma to introduce a quotation.
For example: He said, “I will be there soon.”

Separating introductory elements

Use a comma after an introductory word, phrase, or clause.
For example: “After the game, we went out for dinner.”

Setting off nonrestrictive elements

Use commas to set off nonessential or nonrestrictive elements in a sentence.
For example: “The book, which I bought yesterday, is on the table.”

Separating elements in dates and addresses

Use commas to separate elements in dates and addresses.
For example: “Her birthday is on May 5, 1990.”

Learn about Full Stop (.) in English

Usage of a Comma in English

In English writing, commas are used to indicate pauses, separate ideas, and clarify meaning, among other things. Here are some typical usage scenarios for commas, along with useful examples:

Separating items in a list:
- Example: “She packed her clothes, books, and laptop for the trip.”
Separating adjectives:
- Example: “It was a long, tiring journey.”
Separating clauses:
- Example: “I enjoy swimming, and my brother enjoys running.”
Setting off introductory elements:
- Example: “After finishing his work, he went for a walk.”
Setting off nonrestrictive phrases and clauses:
- Example: “My friend John, who is a doctor, will be visiting us.”
Before coordinating conjunctions in compound sentences:
- Example: “She was tired, but she continued working.”
In direct address:
- Example: “Mary, could you please pass the salt?”
Before or after direct quotations:
- Example: He said, “I will be there soon.”
With dates and addresses:
- Example: “Her birthday is on May 5, 1990.“
Before and after appositives:
- Example: “My brother, the doctor, will be visiting us.”

Usage of a comma in American vs. British English

While the fundamental rules of comma usage are generally consistent across American and British English, there are some subtle differences in style and preference that are worth noting:

Commas in dates: In American English, it is customary to include a comma before the year in a full date. For example: “July 4, 2023.” In British English, the comma is usually omitted: “4 July 2023.”
Commas in addresses: American English typically uses commas to separate elements in addresses, like “123 Main Street, New York, NY.” British English might not always include these commas, especially in more modern styles.
Quotation marks and commas: In American English, commas and periods typically go inside quotation marks, while in British English, they might go outside if they are not part of the quoted material.
Lists and serial comma: In American English, the use of the serial comma (the comma before the final “and” or “or” in a list) is more common and often considered standard. In British English, its usage is more optional and tends to be omitted unless necessary for clarity.

When to Use a Comma

Commas enhance sentence structure and clarity in a variety of situations. Here are some typical situations in which a comma is appropriate:

To separate items in a list: “She bought apples, oranges, and bananas.”
To separate adjectives: “He lived in a small, quaint cottage.”
To separate clauses in a sentence: “She enjoys reading, and he prefers writing.”
To set off introductory elements: “After finishing her homework, she went for a walk.”
To set off nonessential information: “John, who is my neighbor, is a doctor.”
Before or after direct quotations: He said, “I’ll be there soon.”
To set off appositives: “My brother, a lawyer, is visiting next week.”
To separate contrasting elements: “She likes to sing, not dance.”
Before a coordinating conjunction in a compound sentence: “I like to swim, and she likes to run.”
To separate elements in dates and addresses: “Her birthday is on May 5, 1990.”
To indicate a pause in speech or writing for clarity: “Well, I think we should go now.”
Before or after a person’s name when directly addressed: “Jane, can you help me?”

When Not to Use a Comma

Between a subject and its verb: “She plays tennis regularly.”
Between a verb and its direct object: “He enjoys playing the piano.”
Between a preposition and its object: “They walked along the beach.”
Between a relative pronoun (that, which, who) and its antecedent: “The book that she recommended was fascinating.”
In a compound predicate: “She runs and swims every day.”
In certain types of restrictive clauses or phrases: “The car that he bought is blue.”
Between a possessive noun and its object: “John’s car is parked outside.”
Before a subordinating conjunction in a complex sentence: “She left because she was tired.”
Between a verb and its adverb: “She danced gracefully.”
Between parts of a compound word: “The textbook is up-to-date.”

Common Mistakes with a Comma

Comma splices: Connecting two independent clauses with just a comma.

Incorrect: “She was tired, she went to bed.”
Correct: “She was tired, so she went to bed.”

Fused sentences (run-on sentences): Similar to comma splices, this occurs when two independent clauses are joined without any punctuation.

Incorrect: “I like coffee she prefers tea.”
Correct: “I like coffee, but she prefers tea.”

Misplacing commas in a series: Putting a comma after the conjunction in a series.

Incorrect: “He likes to swim, and, play tennis.”
Correct: “He likes to swim, and play tennis.”

Using a comma instead of a semicolon: Incorrectly replacing a semicolon with a comma in a compound sentence.

Incorrect: “The sun was setting, we decided to stay a little longer.”
Correct: “The sun was setting; we decided to stay a little longer.”

Overusing commas: Using too many commas in a sentence, which can make it confusing or choppy.

Incorrect: “She walked into the room, and, saw the book, and, decided to read, it.”
Correct: “She walked into the room, saw the book, and decided to read it.”

Missing commas after introductory elements: Not using a comma after introductory words, phrases, or clauses.

Incorrect: “In the morning I like to go for a run.”
Correct: “In the morning, I like to go for a run.”

Not using a comma before a coordinating conjunction: Failing to use a comma before a coordinating conjunction (and, but, for, nor, or, so, yet) to connect two independent clauses.

Incorrect: “He studied hard but he didn’t pass the exam.”
Correct: “He studied hard, but he didn’t pass the exam.”

Misplacing commas in dates and addresses: Using a comma between the month and the year in dates or placing commas incorrectly in addresses.

Incorrect: “January 1, 2023” (for American English).
Correct: “January 1, 2023.”

Example sentences of a Comma

Here are 50 example sentences that demonstrate the use of commas in various contexts:

She completed her assignment, and then she went for a walk.
The tall, elegant tower stood out among the other buildings.
He bought apples, oranges, and bananas from the market.
After the storm passed, the sun came out.
John, my old friend, is coming to visit us tomorrow.
She excelled in both academics and sports.
The meeting is scheduled for Tuesday, November 15, 2023.
“I’ll be there soon,” he assured her.
Running late, she hurried to catch the bus.
The house, which was built in the 19th century, has a rich history.
We went to the beach, played volleyball, and had a picnic.
Jane, can you please pass me the salt?
He said, “I’ll see you tomorrow.”
In 1920, women were granted the right to vote.
The movie, which was released last week, received rave reviews.
She walked slowly, her feet dragging on the ground.
After the game, they celebrated with pizza and ice cream.
The car, sleek and powerful, sped down the highway.
The concert is scheduled for Saturday, July 8, 2023.
“Please be quiet,” the teacher said firmly.
I need to buy milk, eggs, and bread from the grocery store.
He is a talented, hardworking musician.
On their anniversary, they went to a fancy, expensive restaurant.
The book, a bestseller, has been translated into several languages.
The train arrived, and the passengers disembarked quickly.
The dog, black and white, barked loudly at the mailman.
After the rain stopped, a rainbow appeared in the sky.
“I can’t believe it,” she exclaimed with joy.
The painting, though expensive, was worth every penny.
She cooked a delicious, mouthwatering meal for the guests.
Hiking in the mountains, they enjoyed the breathtaking views.
The team won the game, and the fans cheered enthusiastically.
“Could you please pass me the menu?” he asked politely.
In her purse, she carried her wallet, keys, and phone.
The building, designed by a renowned architect, was a marvel.
The film, released last year, won multiple awards.
After the play ended, the audience gave a standing ovation.
“I’m not sure,” she replied, hesitatingly.
His speech, though brief, was impactful.
She left the office, her mind preoccupied with the day’s events.
The baby, sleeping peacefully, looked angelic.
The car, old and rusty, barely made it up the hill.
The shop, known for its handmade crafts, attracted many tourists.
He was tired, hungry, and frustrated after a long day at work.
The meal, prepared with fresh ingredients, was delicious.
“Let’s go,” she said, excitement evident in her voice.
The museum, open to the public, showcased rare artifacts.
They traveled to Paris, France, for their honeymoon.
The sun, bright and warm, shone down on the beach.
“I’ll call you later,” he promised before hanging up.