Remember that scene in Pirates of the Caribbean when the ugly old pirate Captain Barbarossa says the pirate’s code is “more what you’d call guidelines than actual rules”? Well, that’s the truth about comma rules. Most of what we consider rules of comma usage are actually guidelines from one style guidebook or another. That’s one reason so many people are confused by punctuation. (It’s also why otherwise sensible ELA teachers get enraged and join in flame wars on Facebook.)
Adolescent brains can have difficulty juggling multiple sets of guidelines. For the sake of consistency, I teach these “Comma Rules” based on MLA 8 and Strunk & White’s Elements of Style.
1. Serial comma or Oxford comma
Use a comma after each item (except the last) in a list or series of three or more.
Soccer, lacrosse, and swimming are popular with both males and females.
This is probably one of the most hotly debated “comma rules,” but MLA says to place that comma. Students sometimes overgeneralize and want to add a comma before any and in the sentence. Just remind them that two items is not a list.
You can introduce some intricacies into this rule if you want. Series of words joined by nor do not use commas: “neither snow nor rain nor heat nor gloom of night. . . .” Series that use commas within the items are separated by semicolons: “hot dogs, chili, and nachos; burgers and chips; or chicken strips, catfish, and hush puppies.”
Use a comma after the city (not the state) in a mailing address.
National High School Hall of Fame
P.O. Box 690
Indianapolis, IN 46206
This rule applies to an address on an envelope or package, a letter heading, or a form that requires city, state, and ZIP code. I was astonished the first year I had my yearbook staff write thank you letters to their advertisers. Who were these middle-schoolers who didn’t know how to address an envelope? After that I taught a mini-lesson each year before wasting 30 envelopes on trial-and-error!
Use a comma after each part of a location (city, state or province, country) in a sentence.
We traveled to Indianapolis, Indiana, to visit the National High School Hall of Fame.
It may help to compare the state or country name to a little appositive adding nonessential information. Of course, no comma is necessary when you include only the city or state in the sentence.
Use a comma after the date and year only when all three parts of the date are included.
On December 31, 1938, teams from Kentucky and Connecticut played in a national championship game in Baton Rouge, Louisiana.
This rule applies to dates written in a sentence in the traditional (in the US) sequence of month-date-year. Students are familiar with placing a comma after the date. They may not know to add a comma after the year if the sentence continues.
Use a comma before and after a title or degree following a person’s name.
Ken Griffey, Sr., and Ken Griffey, Jr., both played on major league baseball teams.
This is another case where style guidelines differ. MLA says to use commas before and after any name suffix (academic degree, professional license, etc.) except for Roman numerals. Many other modern style guides omit the commas before and after the suffixes Jr. or Sr.
Use a comma before and after an interjection in a sentence (unless an exclamation mark is used).
Hey, would you like to go to the dance with me after the game?
By definition, an interjection is a nonessential word or phrase in a sentence.
Use a comma between two coordinate adjectives that describe the same noun.
Random drug tests are administered in an attempt to prevent unfair, illegal doping among athletes.
Coordinate adjectives are adjectives of the same rank. Watch out for overgeneralization when students learn the comma rules. They can test whether a comma is needed by switching the order of the two adjectives. If they can be switched and still sound correct, then they are coordinate adjectives.
Use a comma after a transitional or conjunctive adverb.
Students who play sports must divide their time between practicing and studying; however, athletes have a higher mean GPA than non-athletes.
Students may recognize these as the THAMOS adverbs. If you insert a transitional adverb into a sentence or clause somewhere besides the beginning, place commas before and after it.
Use a comma before and after the adverb too meaning “also.”
Dancers, too, spend hours practicing and working out.
Don’t use commas when too means “excessive” like too much punctuation or too many commas!
Use a comma before and after words, phrases, and clauses that show contradiction.
Horseback riding, not skiing, is the most expensive sport.
A tag question or tail question turns a statement into a question and will always be set off by a comma. A dependent clause at the end of a sentence doesn’t usually need a comma. Do add a comma if the subordinating conjunction creates contrast or contradiction. Subordinating conjunctions that create contrast are although, though, even though, even if, even when, and whereas.
Use a comma before beginning and end quotation marks within a sentence.
“We realized,” said an administrator, “that when we kicked kids off the team, they weren’t going to the library instead.”
Attribution or dialogue tag before the quote
Place a comma before the opening quotation marks and capitalize the first word of the quote. Use appropriate end punctuation before the closing quotation marks.
Dialogue tag interrupting the quote
Place a comma before the first closing quotation mark. After the dialogue tag, place a comma before the next opening quotation mark. Continue the quote with lowercase letters. Use appropriate end punctuation before the final closing quotation marks.
Dialogue tag after the quote
Use a comma to replace a period at the end of the quote before the closing quotation marks. If the quote ends with a question or exclamation mark, do not add a comma. Place a period after the dialogue tag to end the sentence.
10. Direct address
Use a comma before and after naming the person or group being addressed.
Coach, I finished selling my raffle tickets for the fundraiser.
Proper noun, common noun, or pronoun–we call the “name” of a person (or group, animal, object, etc.) being addressed the noun of address.
11. Introductory phrases
Use a comma after introductory phrases of more than three words.
Without a natural athletic physique, you can still develop strength and quickness through training, practice, and hard work.
Introductory phrases could be prepositional phrases, participial phrases, infinitive phrases, or absolute phrases. After an introductory phrase of three or fewer words, a comma is optional. Do not place commas between multiple introductory phrases in a row unless they are a list.
12. Compound sentences
Use a comma before a coordinate conjunction joining two independent clauses.
About 1 out of every 30 high school men’s basketball players plays in college, and fewer than 1 in 10,000 eventually play in the NBA.
This is one of the most frequently used and misused comma rules. Two common errors in writing compound sentences are the comma splice and the run-on sentence. A comma splice occurs when a writer joins two independent clauses with a comma, but doesn’t use a coordinate conjunction. A run-on sentence is just the opposite: two clauses joined by a coordinate conjunction without a comma.
Some students may try to add a comma before every coordinate conjunction! This is most likely to be a problem in sentences with a compound predicate. Have students check that both parts of the sentence are clauses by finding both subject-verb pairs.
Another common mistake is placing the comma after the coordinate conjunction. I tell students to remember alphabetical order: COMma comes before CONjunction.
13. Dependent clauses
Use a comma after an adverbial dependent clause.
Because teens’ bones are growing in uneven spurts, muscle and tendon injuries are common in adolescent athletes.
This is one of the most misunderstood comma rules. Students may struggle with this because the rule changes with where the dependent clause appears in the sentence. I worded my rule like this to simplify what students must remember. Now, the only trick is identifying an adverbial clause.
Adverbial clauses begin with subordinating conjunctions. The acronyms SWABI and ON A WHITE BUS are helpful for remembering the most common subordinating conjunctions. If the dependent clause comes at the end of a sentence, don’t add a comma (just end punctuation).
14. Nonessential phrases and clauses
Use a comma before and after nonessential (or parenthetical) words, phrases, or clauses.
The world record for fastest 100-meter hurdles wearing swim fins, held by Christopher Irmsher of Germany, is 14.82 seconds.
Appositive phrases, participial phrases, and absolute phrases may be nonessential or parenthetical phrases. Adjective clauses may be nonessential clauses. To test whether a phrase or clause is nonessential, read the sentence without it. If the meaning remains the same, the phrase or clause is nonessential.
15. To prevent confusion
Use a comma whenever needed to prevent confusion.
Commas help the reader make meaning. They group elements of a sentence together and/or separate them from each other or from the rest of the sentence.
16. Do NOT use a comma
~ between subject and predicate
~ between parts of a compound predicate
~ after the main (independent clause) in a complex sentence
These are the most common situations in which I’ve seen students overuse commas.
Commas and spacing
Do not leave a space before a comma.
Do not leave a space after a comma followed by closing quotation marks.
Leave a space after a comma followed by a word.
Resources to help teach Comma Rules
I developed these resources to use in my own classroom. Now you can purchase them through my website or in my TPT store. Save 20% when you get all these resources in a Comma Rules bundle. Comment below if you have any questions!
Start with the Comma Rules slideshow presentation and interactive notebook flip book. As you teach or review each comma rule using the slideshow, students record notes and highlight examples in their flip books.
Create a bulletin board or hallway display with the Comma Rules poster set. Post them at the beginning of the year or add a new poster with each rule you teach.
For fun review activities, try the Comma Rules scavenger hunt and the infographic poster template. In the scavenger hunt, students find examples of each rule in real life texts from your classroom library. This is a great centers rotation lesson! The infographic poster activity requires students to choose a theme or topic and create an infographic about it. The twist is that each bit of trivia must demonstrate one of the comma rules. It’s a fun partner or group mini-research project. You also end up with some attractive posters to decorate your classroom walls.
Get a Free Comma Rules Audit Checklist
Download this editable PDF chart to track the most common comma errors in your students’ writing.