
I am a member of a critique group. We meet once a week (thank you, Zoom, during this time of pandemic restrictions) where we take turns reading to the group and providing feedback for each other. We joke about our “comma jar,” where we contribute an imaginary dollar for every comma correction made during the feedback comments.
Why are commas so confusing? I tend to put them where I pause while reading. This is an intuitive decision, but unfortunately, it often leads me astray. Others in the group seem to avoid them altogether. Without the commas, their sentences flow onward with no rhythm or cadence. You’ve probably seen the joke: Let’s eat Grandma. Let’s eat, Grandma. Commas save lives! We really need to figure them out.

In 1998, I took a Business Writing class in college, and we made a punctuation Bible. I’ve returned to that spiral notebook time and again (thank you, Dr. Culbert). Here is what he taught us about commas.
Commas precede coordinating conjunctions (and, or, but, for, nor) that join independent clauses.
Ben, Eric, and Mandy will attend the meeting today, but Charlotte won’t be there.
You need to clean your room to receive your allowance, but Zach can help you if you persuade him.
Commas follow long, introductory, adverbial phrases and clauses.
In the middle of their transaction, Marcus and Jim blew up.
Mentally preparing herself for the battle of wills ahead, Sandy made a list of all her reasons for denying Michelle’s request for a tattoo.
However, if the introductory phrase is shorter than four words, you can leave the comma out. (Personally, I tend to include the comma anyway. My fingers type it automatically.)
During the night he heard many noises.
Commas precede, follow, or surround appositives. (Appositives are noun phrases placed side by side so that one element identifies the other in a different way.)
I chained Lady, my adventurous dog, to a tree to keep her from digging under the fence.
During our next school holiday, Thanksgiving break, I’ll take a vacation.
Commas precede, follow, or surround inverted elements. (For when you’re channeling Yoda.)
Too, he loved her.
I, also, have been to the edge.
Commas surround non-restrictive modifiers. A non-restrictive modifier is a word or group of words modifying the subject of a sentence but not restricting it to a particular individual or group. A restrictive modifier restricts the subject to a particular individual or group. Commas surrounding a non-restrictive modifier indicate that we can take it from the sentence without changing the sentence’s essential significance. Therefore, commas must not surround a restrictive modifier. (I confess, I have to Google this one every time. I need lots of examples to cement the definitions.)
restrictive: Men who hate women should not marry. (We don’t use commas to surround “who hate women” because we cannot take it from the sentence without changing the meaning. Men should not marry gives us a completely different meaning than the original sentence.)
non-restrictive: The women, who rode in all three barrel races, love to date cowboys. (The commas surround the modifier because we can remove these words without changing the essential meaning of the sentence.)
restrictive: People who have addictive personalities shouldn’t try smoking. (“Who have addictive personalities” is essential to the sentence – no commas.)
non-restrictive: My brother, who trimmed trees Sunday, came by for dinner. (We can ignore the modifier without changing the meaning of the sentence.)
Commas separate elements in a series. (In a series of three or more elements, if a coordinating conjunction precedes the last element in the series, the comma preceding the conjunction is optional. Enter the Oxford comma argument, which is a post for another day.)
We hired laborers, skilled carpenters, and supervisors for the project. (Since we have included “and” in the series, we can drop the comma after carpenters. I, however, am in the Oxford comma camp, so I choose to keep it.)
We need to buy apples, bags of candy, shaving cream, and decorations.
Commas precede quotation marks.
He asked, “Will you marry me?”
I answered, “You can go if your room is clean.”
Commas surround simple interrupters.
I’ll see you tonight about, let’s see, 7:00 pm.
It was over, um, two years ago.
Use commas to separate adjectives of equal rank. (If we could place the word and between two adjectives without changing the meaning of the sentence, then the adjectives are considered equal. Here is an example:
She spoke in a thoughtful, precise manner. (The phrase with the conjunction included — “thoughtful and precise” — gives the sentence the same meaning, therefore, replace and with the comma.
She wore a cheap fur coat. (Including the and between “cheap and fur” doesn’t give the same meaning. No comma.)
Common mistakes:
Using a comma when a sentence has two clauses, but both have the same (implied) subject. If two or more verbs go with the same subject, you don’t need a comma because you don’t have multiple independent clauses.
We are visiting Washington and also plan a side trip to Baltimore. (The subject of both phrases is “we” — no comma necessary.
Commas always, always, always go inside the quotation mark.
“That’s simple,” the student said.
When including city and state names, use commas after both.
His journey took him from Fargo, North Dakota, to Burleson, Texas.
Commas aren’t needed after conjunctions that begin sentences.
But I was afraid to open the door.
Commas, commas, commas. I’ve accepted the reality that I’m gonna put a dollar in the comma jar at least once each meeting with my critique partners. It’s my goal to make it through an entire chapter reading with no corrections. One day!

What about you? What are your common mistakes? Share with us what you’ve learned through your writing journey.