- Demonstrate the standard uses of commas with conjunctions and in lists
Coordinating Conjunctions: FANBOYS
Coordinating conjunctions are words that join two words or phrases of equal importance. The mnemonic FANBOYS helps us remember the seven most common:
When these conjunctions join two words or phrases, no comma is necessary.
- Paula and Lucca had a great time on their date.
- Minh turned off the lights but left the door unlocked.
- We bought tickets so we could go to the concert.
However, when these conjunctions are used to join two complete ideas, a comma is required:
- Danny studied the lifespan of rhinoceroses in their native Kenya, and he also studied the lifespan of rhinoceroses in captivity.
- We could write this as two separate sentences, but we’ve chosen to join them together here.
- There is an accident on the highway, so you and Mom should take an alternate route.
Watch this video below to see when to use commas with coordinating conjunctions, and to understand why you don’t need them with other types of transition words:
You can view the transcript for “Comma story- Terisa Folaron” here (opens in new window).
Commas in Lists
Perhaps one of the most hotly contested comma rules is the case of the serial comma, or Oxford comma. MLA style (as well as APA and Chicago) requires the use of the serial comma—AP style (Associated Press style commonly used by news outlets) highly recommends leaving it out. But what is the serial comma?
The serial comma is the comma before the conjunction (and, or, and nor) in a series involving a parallel list of three or more things. For example, “I am industrious, resourceful, and loyal.” The serial comma can provide clarity in certain situations. For example, if the “and” is part of a series of three or more phrases (groups of words) as opposed to single words:
- Medical histories taken about each subject included smoking history, frequency of exercise, current height and weight, and recent weight gain.
The serial comma can also prevent the end of a series from appearing to be a parenthetical:
- I’d like to thank my sisters, Beyoncé and Rhianna.
Without the serial comma, it may appear that the speaker is thanking his or her two sisters, who are named Beyoncé and Rhianna (which could be possible but isn’t true in this case). By adding the serial comma, it becomes clear that the speaker is thanking his or her sisters, as well as the two famous singers: “I’d like to thank my sisters, Beyoncé, and Rhianna.”
By always using a comma before the “and” in any series of three or more, you honor the distinctions between each of the separated items, and you avoid any potential reader confusion.
This video explains the reasons why the serial or Oxford comma is still up for debate, and how you can decide when to use it.
Note: Some professors and many academic journals prefer to leave out the serial comma (for the journals, it is literally cheaper to print fewer commas). Because of this, the serial comma is not recommended in AP style.
See if you can place the commas or semicolons in their correct locations in the following interactive.