What Are Commas? (with Examples)

by Craig Shrives

Commas

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

Read more about using commas.

How Commas Are Used

Here is a quick overview on how commas are used:

(1) 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.)
The introduction is often an adverbial phrase or an adverbial clause.

Read more about using a comma after "setting the scene

(2) 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.)
A "transitional phrase" is also called a conjunctive adverb.

Read more about using a comma after a transitional phrase.

(3) 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) 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) 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) 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) 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) With numbers to aid reading.

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) 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) 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. Read more about the vocative case.

Other Punctuation Marks

Here is a slider with lessons to the other punctuation marks:

Why Should I Care about Commas?

It is worth investing time in learning how to use commas correctly. Lots of writers fly by the seat of their pants when it comes to commas. Sometimes, they get it right, but sometimes they get it wrong. Getting good with commas (especially with how they divide phrases and clauses) will make you a far more confident writer. And, your writing will become much easier to read.

Read our main page about using commas.
Take a test on using commas.

Key Point

  • Give up the guesswork. Learn how to use commas properly.
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See Also

Take a test on commas. Take another test on commas. Much more about using commas What is punctuation? What are apostrophes? What are colons? 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