General rules:

  • Only use commas when necessary for clarity or when following a particular rule.
  • For help with commas outside of rules explained in this guide, AP defers to the comma usage guide in Webster’s New World College Dictionary, Fourth Edition.
  • Use commas consistently in similar situations throughout an entire article.


Commas in a Series (Serial Comma)


Simple series: Separate elements in a series, but omit the comma right before the conjunction in a simple series.

  • Example: Before you start, collect signatures, addresses and contact emails.

Conjunction within the series: If an important element in a series uses a conjunction, use the comma before the concluding conjunction in the series.
  • Example: The complimentary breakfast consists of hash browns, toast, and ham and eggs.
  • Example: XYZ Company handles start-ups, mergers and acquisitions, and buyouts.

Complex series: Include the comma before the concluding list element in a complex series.
  • Example: The big difference lies in whether you intend to visit each part of the city, whether you want to hit all the major cultural exhibits, or whether you want to take in some of the city’s hidden gems.


Commas With Conjunctions

Compound sentences: Use a comma before coordinating conjunctions (and, but, for; mnemonic FANBOYS) that connect two complete sentences.

  • Example: The writer followed AP style, and he referenced his guide frequently.

Complex sentences: Usually this comma is necessary when the subjects of each clause are clearly stated, but no comma is necessary when the subject is shared between the clauses.
  • Example: They plan on visiting the museums and intend to catch a play as well (shared subject of “they”).


Imperative sentences: Keep in mind that imperative sentences where “you” is implied are independent sentences. Connecting two imperative sentences requires the comma, because each clause has its own subject even if the subject is the same.

  • Example: Connect the pieces, and sand the rough edges.

Commas With Direct Quotations


Introducing direct quotations: Use a comma when introducing direct quotes consisting of one sentence within a paragraph, and do not use a comma when quoting a partial or indirect quotation.

  • Example: Jordan says, “The trip to Russia was an experience the students are unlikely to forget.”
  • Example: He claimed the experience was “one of the best of his life.”


Introducing quotations of more than one sentence: Use a colon to introduce direct quotations of more than one sentence.


Attributing direct quotations to a source: Use a comma and not a period after a direct quotation to show attribution.

  • Example: “The night is still young,” stated her date.


Commas With Adjectives (Coordinate Adjectives)


Adjectives with equal rank: Use commas between adjectives that are equal in rank. When you can replace a comma with “and” without changing the meaning, the adjectives are equal.

  • Example: a long, winding road
  • Example: a brightly lit, crime-free area


Adjectives with unequal rank: If the last adjective outranks previous adjectives because it is an essential part of a noun phrase, omit the comma.

  • Example: an expensive fur coat (fur coat is a noun phrase)
  • Example: the yellow baseball cap (baseball cap is a noun phrase)


Commas With Essential/Nonessential Clauses and Phrases


Rule: Offset nonessential clauses and phrases with a comma. Omit offsetting commas with essential clauses and phrases.

  • Example: Writers who don’t proofread their work should not get upset over editorial comments.
  • Example: Writers, especially the ones who clearly don’t proofread, should not take issue with comments from an editor.


Commas With Introductory Elements


Four words or greater: Use a comma between an introductory clause or phrase and the main clause.

  • Example: When you no longer enjoy city life, move to the country.


Three words or fewer: You can omit this comma after short introductory phrases if no confusion results, but use the comma if comprehension is hurt by its omission.

  • Example: During the day you do not need to lock the door.

Commas With Hometowns/Ages


Rule: Use offsetting commas when a person’s hometown or age is used as an appositive.

  • Example: Samuel Perkins, Kansas City, Missouri, finished in first place.
  • Example: Sarah Jenkins, 37, was the first on the scene.


Commas With Dates


Rule: When referring to only a month and a year, do not set off the year with commas.

  • Example: February 1989 holds the record for snowiest month in history.


Rule: When referring to a month, day and year, set off the year with commas.

  • Example: February 24, 1989, had the most amount of snow that month.