Jennifer posted this discussion thread on commas
last week. I responded to that discussion, but giving it more thought this weekend, I began to wonder how I, a layperson if you will, would describe to another person the rules of using commas.
This is what I came up with:
The purpose of a sentence is to convey an idea or message. When speaking or writing, our goal should be to convey the idea or message clearly and efficiently.
In a sentence, the comma serves as a brief pause in the flow of information. In most cases, we do not want to insert a pause into the sentence, unless it is required for clarity or emphasis, until the message of the sentence is fully realized—until we have conveyed our meaning.
Look at commas as though they are speed bumps in a parking lot or school zone. The speed bumps help to slow down the flow of traffic in areas where we need them to—parking lots and school zones—places where there are pedestrians and cars. However, we don’t need speed bumps on the freeway because it is both undesirable and unnecessary to slow down traffic in these areas.
So let’s start with some basic sentences:
He chose the blue sweater and paid for it with the money he got for his birthday.
I think we should go see a movie this evening.
We had a fun time at the party.
We weren’t late for the wedding.
We never had any problems with my in-laws.
I heard about their engagement just this morning.
Here is how these sentences could be incorrectly
punctuated with a comma:
He chose the blue sweater and paid for it, with the money he got, for his birthday.
I think we should go, see a movie this evening.
We had a fun time, at the party.
We, weren’t late for the wedding.
We never, had any problems with my in-laws.
I heard about their engagement just, this morning
Those are glaring mistakes, and I think anyone here can see that. However, I’ve made them this bad for demonstrative purposes only, as I’m certain no one here would make those mistakes.
Obviously, they are incorrect because they interrupt the message, or idea, before it is fully communicated. They are speed bumps in the wrong place, and they are clearly unnecessary and intrusive.
Of course, there is some leeway when using commas in sentences, depending on the intent of the writer or speaker. As a general rule though, I would offer this advice:
1. We want to use a comma, or commas, when we choose to insert information into a sentence that is not essential to the idea (or message) being conveyed. These can be a single word or group of words that modify, illustrate, define, clarify, or emphasize the essential meaning of the sentence, but which are not critical to understanding the core idea. (Remember that speed bumps don’t affect our ability
to drive, only the speed
at which we drive.)
If the word or words are inserted at the start of a sentence, they need to be followed by a comma.
They need to be preceded by a comma, if inserted at the end of a sentence.
If inserted into the middle of the sentence, like they are in the sentence you are reading right now, they need to be enclosed by two commas.
He chose the blue sweater, my least favorite of the group, and paid for it with the money he got for his birthday.
Instead of staying home, I think we should go see a movie this evening.
We had a fun time at the party, all things considered.
Luckily, we weren’t late for the wedding.
To my amazement, we never had any problems with my in-laws.
I heard about their sudden, and quite unexpected, engagement just this morning.
In these examples given, the additional word or words help to modify, illustrate, define, clarify, or emphasize the essential meaning of the sentence, but they are not critical to understanding what is being communicated. The words in bold could be eliminated and the intention—or meaning—of the sentence would still be the same.
Of course, that does not mean that all words that modify, illustrate, define, clarify, or emphasize must be set off by commas. Adverbs and adjectives frequently do not need commas. Here are the same sentences re-written again:
He chose the ugliest blue sweater, my least favorite of the group, and quickly paid for it with his birthday money.
Instead of staying home, I really think we should go see a decent movie this evening.
We had an especially fun time at the party, all things considered.
Luckily, we weren’t too late for their stupid wedding.
To my amazement, we never had any problems with my irascible in-laws.
I heard about their all-too-sudden, and quite unexpected, engagement just this very morning.
2. The second function of the comma is to help distinguish meaning and intention when listing items in a sentence. They essentially help us organize the information so that our meaning is clear.
Here is a sentence in which they are completely left out:
We had peanut butter and jelly ham and cheese and tuna salad sandwiches.
Obviously, that is way too confusing. How many sandwiches were there? Is there such a thing as jelly ham? Was it just one sandwich that had PBJ, ham, cheese, and tuna salad on it? It could be read that way.
Here is the same sentence with the commas glaringly misplaced:
We had peanut butter, and jelly ham, and cheese and tuna, salad sandwiches.
Written this way, it implies we had four kinds of sandwiches: one kind with peanut butter, one with jelly ham, one with cheese and tuna, and one that was a salad sandwich. (What the heck is jelly ham
, and what is a salad sandwich?)
Here is the sentence written with the commas inserted correctly:
We had peanut butter and jelly, ham and cheese, and tuna salad sandwiches.
Once the commas are in the correct place, we can clearly see that we had three kinds of delicious sandwiches: one kind with peanut butter and jelly, one with ham and cheese, and one with tuna salad.
Now let’s build a more complex sentence:
We had a wide variety of sandwiches at the picnic, including peanut butter, peanut butter and jelly, turkey and cheese, ham and cheese on whole wheat, chicken salad with mustard, chicken salad with mayo, liverwurst on rye, BLTs, and tuna salad.
How many different kinds of sandwiches did we have at this picnic? I count nine. Most notably I can clearly see that we had two kinds of peanut butter sandwiches; one without jelly and one with jelly. We also had two kinds of chicken salad; one with mustard and one with mayo. I also indicated, without any confusion, that the ham and cheese sandwiches were definitely on whole wheat, and that the liverwurst sandwiches were definitely on rye.
When not to use a comma
We cannot use a comma to conjoin two independent clauses, unless we add a conjunction, too. Doing this creates a comma splice.
Correct (two independent clauses): We went to see
Gone with the Wind. John went to see
The Matrix instead.
Incorrect (comma splice): We went to see
Gone with the Wind, John went to see
The Matrix instead.
Correct (comma with conjunction): We went to see
Gone with the Wind, but John went to see
The Matrix instead.
Also correct (with semi-colon joining two independent clauses): We went to see
Gone with the Wind; John went to see
The Matrix instead.
Completely leaving out a period, a comma with a conjunction, or a semi-colon creates a run-on sentence:
Incorrect: We went to see
Gone with the Wind John went to see
The Matrix instead.
Leeway in writing with commas
Earlier I mentioned that there was some leeway in using commas in a sentence. Here is one example of how the presence or absence of commas can affect a sentence.
This is not an issue about black Americans, or white Americans, or Native Americans, or Jewish Americans, or even Hispanic Americans; this is about equal access and opportunity for all Americans.
Now read the second example, with all of the commas removed:
This is not an issue about black Americans or white Americans or Native Americans or Jewish Americans or even Hispanic Americans; this is about equal access and opportunity for all Americans.
What is the difference in these two sentences? The words haven’t changed, and the meaning hasn’t changed, but the emphasis has.
The first sentence is a much slower-paced and thoughtful sentence, as if the speaker chose his words carefully and precisely. He wanted to be all-inclusive and completely understood.
The second sentence, now that the speed bumps have been removed, is a much more urgent and emphatic sentence that shows the enthusiasm and conviction—and perhaps even anger—of the speaker.
Both are, to my understanding, absolutely correct. They are just different ways of writing, speaking, hearing, or comprehending the sentence. The tone of the sentence can be manipulated by the presence or absence of the commas.
As always, I welcome corrections, observations and comments on this discussion. I enjoyed writing this because it really does help to organize one’s thoughts if you put it down on paper (or monitor).