This document provides guidelines for using commas in different situations: 1) Use a comma before coordinating conjunctions when joining two independent clauses. 2) Use commas around introductory clauses that indicate when, where, how or why. 3) Use commas around nonessential clauses, which are clauses that are not essential to the meaning of the sentence.

1. Common Comma Situations
Coordinating Conjunctions
When joining two independent clauses, use a comma withfor, and, nor, but, or, yet, so.
Uncommon Objects is a well-known vintage shop, and it is located on South Congress Avenue.
Introductory Clauses
These clauses often illustrate when, where, how, or why. Common words for introductory clauses areafter, although, as, because, if, since, when, while.
While we were eating at Kerby Lane, we talked about magnificent bats.
Because the bat is Austin’s most iconic animal, many vampires move to this city.
If you like bats, you should hang out on the Congress Avenue Bridge at dusk.
Nonessential Clauses
Put commas around nonessential clauses.
Austin City Limits festival, in recent years, has taken place in Zilker Park. SXSW, on the other hand, is held throughout the city.
The Mohawk, which is located on Red River Street, is one of Austin’s many rock venues.
Most of Austin’s university students attend the University of Texas at Austin. Some Austinites, however, commute to Texas State.
Quick test:
If you leave out the word or phrase, will the sentence still make sense?
Does the sentence make sense if you move the word or phrase to a different position?
Series
Use commas to separate three or more items in a series.
Some food trucks in Austin offer Mexican, Korean, or Japanese food.

2. Commas with Adjectives
Use a comma with two or more adjectives if the words are equally important.
Coordinate
The capitol presents a proud, comforting image when it is lit up at night.
When the Green Belt is dry, the water beds become pungent, gooey, nasty puddles.
Non-coordinate
He often wore his threadbare cotton Longhorn shirt to perfectly nice dinner parties.
She wore her snazzy snakeskin boots to the Broken Spoke.
Quick test for coordinate adjectives:
Can you switch the order of the adjectives?
Can you use the word and between the adjectives?
Conjunctive Adverbs
Transitional adverbs or phrases between independent clauses require both a semicolon and a comma. Some of these transitions include therefore,
however, moreover, for example, as a matter of fact, in other words.
Bouldin Creek Coffee House serves the wonderful Tarzan Salad; moreover, the menu offersNutella lattes.
Names and Dates
Austin, Texas, is said to be the live music capital of the world.
December 31, 1999, was a scary night to be in downtown Austin. There were riot police everywhere.
Quotations
Insert a comma when using a signal phrase with a direct quotation.
My grandmother ordered, “Take me to the bluebonnets!”
“Hold on a second,” I said, “so I can put on some pants.”
Created by the English tutors of South Austin Learning Lab, Austin Community College