Comma Rules

TEST: DO NOT try to answer these using the strategy of putting a comma where there is a “natural pause” or “breath” in the sentence. Instead, begin to practice mentally running down this list of comma rules.

1. Use commas to separate items in a series

If more than two items are listed in a series, they should be separated by commas.

My recipe for buttermilk biscuits includes flour, baking soda, salt, lard, and buttermilk.

Commas should not be placed before the first element or after the last element of a series.

WRONG: My recipe for banana bread includes, flour, baking soda, bananas, sugar, and eggs.

WRONG: Flour, baking soda, sugar, bananas, and eggs, are the ingredients to my banana bread.

2. Use a pair of commas together to set off non-essential phrases and clauses. To test this, read the sentence without what’s between the commas and see if it makes sense.

If a phrase or clause is not necessary to the sentence’s main idea, it should be set off by commas.

Nina, who has never had any formal chef’s training, bakes an excellent cheesecake.

Since the sentence makes sense without the intervening clause, which merely serves as further description of Nina, the clause should be set off by commas.

If a phrase or clause is necessary to the meaning of the sentence, it should not be set off by commas.

WRONG: We crossed, over the Mississippi River, during our vacation.

Since the sentence does not make sense without the intervening clause, the commas are incorrect.

3. Use commas after an introductory dependent clause or transition term.

If a descriptive phrase or clause begins a sentence, it should be set off from the rest of the sentence by a comma.

Having watered his daffodils every day during the drought, Harold was disappointed when aphids destroyed his garden.

After the banquet, Dan and Melissa went dancing.

Notice that the dependent clauses in the beginning of these examples are describing something. The answer to whatever they’re describing MUST come right after the comma.

WRONG: Dripping with grease, Grandma put the casserole on the table.

This is saying that grandma is dripping with grease! Since the introductory phrase is about the casserole, the casserole must be the word after the comma.

RIGHT: Dripping with grease, the casserole sat on the table.

 Don’t forget you can use a comma after a transition term.

However, I don’t think that’s a good idea.

Therefore, Sarah played in the hockey game that afternoon.

Moreover, beavers play a vital role in the ecosystem of a river. 

4. Use commas with FANBOYS to combine two sentences.

For And Nor But Or Yet So

Marta is good at basketball, but she is better at Water Polo.

Cooking good barbecue food takes many hours, and most people don’t have the patience or time for this.

5. Use a comma to end a sentence with a dependent clause.

Jane walked down the pier, laughing the entire way.

The governor enjoyed an afternoon of fly-fishing, a sport popular in Pennsylvania.

6. Commas are used to enter and leave quotes. They always go to the LEFT of the closest quotation mark.

Margaret wrote, “I will never forget you, Hamlet,” on the bathroom wall.

Phillip asked, “Do you want to borrow my car?”

7. Use commas to set off a title after a proper name.  DO NOT use commas if the title comes first.

Dr. Martin Smith, professor of biology at Princeton University, was the speaker at the conference.

Princeton University professor of biology Dr. Martin Smith was the speaker at the conference.

Traps

Separating two sentences with a comma but without one of the fanboys.
 
            WRONGCraig loves to ride his bike to work, therefore, he doesn’t think he needs a car.

The part to the left of the first comma is a sentence. The part to the right of the second comma is a sentence. To connect two sentences with a comma you must use the FANBOYS.
 
            WRONGCooking paella involves many ingredients, none of the ingredients are more important than the salt.

Again, this is two sentences connected by a comma, but with no FANBOYS.