Welcome!
Welcome to the Learning Commons Quick Start Guide on commas!
Commas are a powerful but potentially difficult punctuation mark to use correctly. This guide will cover seven rules for English comma use to help improve your writing.
This guide will explain:
- the importance of commas
- the 7 comma rules
Commas 101
These videos introduce the main uses of commas in English, showing that they:
- Separate items in a list.
- Link two independent clauses together with a coordinating conjunction.
- Set off the introductory element of a sentence.
- Insert non-defining information into a sentence.
Course Information
Course Level: Beginner
Time to Complete: <10 mins
Perfect for: Students in WRTG100/101, ENGL103, or anyone who needs a refresher.
Guide Creator: Abby Pernsteiner
Lists, Compound Sentences, and Establishing Information
Rule #1: Lists
Use commas to separate three or more words, phrases, or clauses written in a series or list.
Example: I drove home, cooked dinner, and got ready for the party.
Note about the Oxford Comma
In a list, the final comma before the conjunction is known as the “Oxford comma”, as in the phrase above: “cooked dinner, and got ready for the party.” This is an academically contentious comma. Some style guides and instructors will recommend going without, so the sentence in that case would read: “I drove home, cooked dinner and got ready for the party.”
Ultimately neither way is necessarily “incorrect”, and you as a writer are free to choose either! However, be consistent throughout your writing, and be sure to use your discretion about careful phrasing. As one author found out, there is a big difference between “I’d like to thank my parents, Ayn Rand and God” and “I’d like to thank my parents, Ayn Rand, and God.”
Rule #2: Compound Sentences
Use commas to separate independent clauses when they are joined by any of these seven coordinating conjunctions (FANBOYS): for, and, nor, but, or, yet, so.
Example: He needed some cash, so he went to the ATM.
Rule #3: Establishing Information
Use commas after introductory a) clauses, b) phrases, or c) words that come before the main clause.
Example: To be honest, I didn’t like the movie.
Example: According to the Bible, Joshua was the son of Nun.
Your Turn: Test Your Understanding
Think you have a grasp of the information above? Test yourself!
Rule #4: Extra Information
Use commas to set off clauses, phrases, and words that are not essential to the meaning of the sentence.
Hint: if you read the sentence without the words in between the commas, the sentence should still make sense.
Example: Dr. Yang, a pediatrician, completed his check-up.
Example: I drove the car, which belonged to my brother, to the mechanic.
Your Turn: Test Your Understanding!
Rule #5: Dates, Numbers, and Places
Use commas to properly punctuate dates, numbers, and places.
Example: He was born on August 3, 1999.
Example: The United States is a country of approximately 300,000,000 people.
Example: July 4, 1776, is known as the day America won independence.
Example: Washington, D.C., is the capital of the United States. Many people from Frederick, Maryland, and Alexandria, Virginia, commute into the city to work every day.
Note: The year, abbreviation, and state names in the above sentence above count as extra information (See Rule #4). Even if this information is critical to the meaning, we conventionally separate it from the rest of the sentence using commas specifically with dates and place names when two pieces of date or place information are used together. Without the year, the sentence would read: “July 4 is known as the day America won independence”, and without the date, the sentence would read: “1776 is known as the year America won independence.” These are both complete sentences.
The same goes for the following two sentences without the place modifiers: “Washington is the capital of the United States. Many people from Frederick and Alexandria commute into the city to work each day.” Also consider: “D.C. is the capital of the United States. Many people from Maryland and Virginia commute into the city to work each day.”.
Your Turn: Test Your Understanding!
Rule #6: Quotes
Use commas to introduce certain quoted material.
A comma must be used to introduce a quote if the quote is an independent clause.
Example: Walt Whitman demonstrates his carefree attitude when he proclaims, “I wear my hat as I please, indoors or out.”
However, a comma is not used if the quote is a dependent clause or phrase.
Example: He considers himself above societal norms, wearing his hat “indoors and out.”
Rule #7: Coordinate Adjectives
Use commas to separate two or more coordinate adjectives that describe the same noun. Be sure not to add an extra comma between the final adjective and the noun itself or to use commas with non-coordinate adjectives.
Coordinate adjectives are adjectives with equal (“co”-ordinate) status in describing the noun; neither adjective is less than (subordinate to) the other. You can decide if two adjectives in a row are coordinate by asking the following questions:
- Does the sentence make sense if the adjectives are written in reverse order?
- Does the sentence make sense if the adjectives are written with and between them?
If you answer yes to these questions, then the adjectives are coordinate and should be separated by a comma. Here are some examples of coordinate and non-coordinate adjectives:
- Scrooge was a cold, unfeeling man. (coordinate: use a comma) Consider: “Scrooge was an unfeeling, cold man” makes perfect sense.
- He wore a large wool sweater. (non-coordinate: do not use a comma) Consider: “He wore a wool, large sweater” sounds weird because “wool” tells us more about the sweater’s basic properties than “large” does.
- The boys crawled into the decrepit school building. (non-coordinate: do not use a comma) Consider: “The boys crawled into the school, decrepit building” does not work at all because “decrepit” does not tell us anything at all about the kind of building.
- I winced at the bright, piercing light. (coordinate: use a comma) Consider: “I winced at the piercing, bright light” sounds fine.
Your Turn: Test Your Understanding!
Wrap-up and self-check
Congratulations!
Now, return to the Learning Commons Resource Moodle and do the exit quiz to confirm your new knowledge!
Additonal Resources
Below are some great links to follow if you want to read more on commas:
Links to the Intro videos:
Links to handouts: