What Are Commas? (with Examples)

What Are Commas? (with Examples)

A comma (,) is a punctuation mark used to mark the divisions in text (as may be caused by phrases, clauses or conjunctions). Commas are used in lists to separate list items and in numbers to aid reading.

Below is a quick overview of when commas are used. Click here for a more comprehensive version of this list or click on the "Read more" link with each entry.

When to Use Commas (A Very Quick Overview)

Below is a quick overview on when to use commas.

(1) Use a comma after phrase or clause that "sets the scene" at the start of a sentence.
  • When I went to Paris, they just stared at me when I tried to speak French.
    • (The "introduction" is shaded.)
Read more about using a comma after setting the scene

(2) Use a comma after a transitional phrase at the start of a sentence.

A transitional phrase is a term like However, Consequently, Therefore, and As a result.
  • Lee has eaten at least two pies a day for the last year. As a result, he has been placed in a high-risk group for diabetes.
    • (The transitional phrase is shaded.)
Read more about using a comma after a transitional phrase.

(3) Use a comma after an interjection.

An interjection is usually a short word inserted into a sentence to express an emotion or feeling.
  • Yes, my horse won.
    • (The interjection is shaded.)
Read more about using a comma after an interjection.

(4) Use a comma before a conjunction that joins two independent clauses.

Words like and, or, and but are known as conjunctions.
  • Lee cannot sing, but he can dance
    • (Here, the conjunction but is joining two the independent clauses Lee cannot sing and he can dance.)
Read more about using a comma before a conjunction.
Read about the Oxford Comma.

(5) Use commas as parentheses to offset a parenthesis.

Parentheses are punctuation marks (either commas, dashes or brackets) used in pairs to offset additional information in a sentence (known as a parenthesis).
  • The case has, in some respects, been not entirely devoid of interest.
Read more about using commas for parentheses.

(6) Use commas to separate list items.
  • Fish, chips, and peas
Read more about using commas in lists and whether the comma after the penultimate list item is required.

(7) Use a comma after a long subject if it aids your readers
  • Leaving a list of Internet passwords, increasing your life insurance and writing a will, will give you peace of mind while you are on operations.
    • (The long subject is shaded.)
Read more about using a comma with a long subject.

(8) Use commas with numbers.

Commas can be used every 3 decimal places in large numbers to make them more readable.
  • 3,356
Read more about using commas with numbers.

(9) Use commas before quotation marks when the quotation is introduced.
  • He said jokingly, "The world is my lobster."
Read more about using a comma before speech marks.

(10) Use commas to offset words in the vocative case.
  • I know your sister, David.
    • (The word in the vocative case is shaded.)
Read more about using a comma when addressing someone.

See Also

Much more about using commas What is punctuation? What are apostrophes? What are colons? What are commas?
What are dashes? What is ellipsis? What are exclamation marks? What are hyphens? What is a full stop / period? What are parentheses (i.e., brackets)? What are questions marks? What are quotation marks? What are semicolons? Glossary of grammatical terms