Core Grammar #7: Commas

Comma Panic

Commas are not part of spoken English, though some people think that they are. (You often hear the advice to put in a comma "whenever you pause" or "whenever you take a breath." That advice is only about 30% accurate.) Like other punctuation, the comma is a written device to help readers figure out how to group things. As you read the material below:

Things Commas Don't Do

1. Don't use a comma to separate the subject and verb.

Do not put a comma between a subject and verb, even if the subject is huge:

Don't write:
The reason I didn't tell you about cracking up the car and having to spend the night in jail, is that I simply forgot.

2. Don't use a comma to separate a verb from the rest of the predicate.

The basic unit of an English sentence is subject-verb-object. Don't break up this group. Spoken English often puts in a pause/gasp/wheeze to indicate an object complement; written English uses the word "that":

Spoken English:
The problem with Uncle Earl is [pause & sigh] he drinks.
Writing trying to keep the rhythm of spoken English:
The problem with Uncle Earl is, he drinks.
Written English acting like written English:
The problem with Uncle Earl is that he drinks.

3. Don't use a comma to separate conjunctions from their following clauses.

Here's another rhetorical unit that really must stay together. There's no logical reason (except the panic of a student who doesn't remember what to do) for separating these:

Don't write:
I never showed up because, my parents wouldn't let me have the car.

This error is very common when sentences begin with a conjunction. Yes, the clause usually must end with a comma, but don't cut off the conjunction from the clause it governs:

Don't write:
Although, she is my sister I love her.
Do it this way:
Although she is my sister, I love her.

4. Don't use a comma to join two sentences without a coordinating conjunction.

Don't write
We are in love, we plan to get married.

That one needs more surgery than simply shoving a comma around. It's got to have a semicolon OR a period and a capital letter OR a comma plus one of the seven coordinating conjunctions (for, and, nor, but, or, yet, so). If it gets a coordinating conjunction, the comma must go before, not after:

Don't write
My father likes to hunt deer but, I like to fish.
Do it this way:
My father likes to hunt deer, but I like to fish.

Words like however, nevertheless, and therefore aren't coordinating conjunctions, so if you want to use them to join two sentences, you must use a semicolon:

Do it this way:
We are in love; therefore, we plan to get married.

Don't use a comma "whenever you breathe."

Heavy smokers don't need more commas when they write. This is yet one more place where written English is different from spoken. If you want to mark a copy for public reading, go ahead and put in some sort of symbol where you think you want to take a breath. (You probably should have some rhetorical logic to the placement of those breathing marks, by the way.) Most writing isn't intended for public reading, though, and the function of a comma isn't to help your need for oxygen; it's a grammatical symbol to help the reader figure out what things should be grouped together.

Commas in lists

I'm sure you know to put commas between items in lists. Some books say that the comma before the final "and" is optional, but it often helps avoid confusion:

I told my son to pick up his socks, take care of all the trash lying around his room, and feed the dog.

Dropping that comma sometimes makes a lot of trouble:

I would like to thank my parents, Martha Stewart and God.

Much better with that "Harvard comma":

I would like to thank my parents, Martha Stewart, and God.

Though there are commas within a list, you do not use one to get the list started or to finish it. The red commas are wrong in these samples:

My shopping list includes, beans, tomato sauce, and ground beef.
Dolmades, pastitsio, and moussaka, were all on the menu at the Greek restaurant.

Commas that get lost

In 2005, Andrea A. Lunsford and Karen Lunsford collected and read several thousand college freshman papers, looking for the most common grammar and mechanical errors. Then they tabulated a list of the top 20 mechanical and grammatical errors made by college freshmen. Here are the comma problems that made the top 20:

#2: Missing comma after an introductory element

This sentence needs a comma after done. Do not put it after Determined.

Determined to get the job done, we worked all weekend.

#6: Mechanical error with a quotation

Use a comma after "speaking" verbs like said, commented, yelled, asked and the like:

Waldo asked, "Is there any more ham?"
My teacher said, "You have the writing ability of a dog."

Quotations that are introduced without speaking verbs do not get that comma. (This is fairly common in academic writing.)

Rawlins says that the comma is the punctuation that is "the hardest to master."
Don't write:
Rawlins says that the comma is the punctuation that is, "the hardest to master."
(The word is is not a synonym for says; it's not a speaking verb.)

#7: Unnecessary comma

Do not panic and throw in a comma when you suspect it's been too long since you hit the punctuation; have a good reason for it.

One very common error is to put commas around restrictive elements (they have to be there for the sentence to make sense). The commas are a signal that the material is optional. In the example below, the phrase about blood donation is essential to the meaning of the sentence, so we don't set it off with commas. (A sharp reader who sees the sentence below will stay home because it says all employees may take the afternoon off, and some of them wish to donate blood.)

All employees, who wish to donate blood, may take the afternoon off.

#11: Missing comma with a nonrestrictive element

Both samples below are wrong because a comma is required both before and after the nonrestrictive clause: Marina, who was president of the club, was first to speak.

#13: Missing comma in a compound sentence

In the sentence below, the comma before "but" is missing. English has seven coordinating conjunctions: for, and, nor, but, or, yet, and so. You can use them with a comma BEFORE to join two independent clauses.

The words "I do" may sound simple but they mean a life commitment.

More information:

Help from the computer:

Microsoft Word will sometimes give you good advice about commas, but it's often wrong. You should know the rule instead of blindly following the computer's advice.

The way I mark things:

If a comma is missing, I will just put it in and circle it so you can find it. If you put in one too many, I will circle it with a strike through the circle (similar to those European traffic signs).


Lunsford, Andrea A., Paul Kei, and Christine M. Lunsford EasyWriter with 2009 MLA and 2010 APA Updates: A Pocket Reference. 4th. Boston: Bedford/St. Martins, 2009. Print.

Rawlins, Jack. The Writer's Way. 6th. Boston: Houghton, 2005. Print.


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The contents of this page have not been reviewed or approved by Ashland University.
Revised 8/10/17 • Page author: Curtis Allen • e-mail: callen@ashland.edu.