It is said that 90% of all writers use a comma correctly 75% of the time, but only 1% of the writers use the comma correctly 99% of the time. Many of us who write for business are in that top 90%. The comma is important. Commas let your writings breathe.
They are the main device by which the grouping of words, phrases, and clauses are set up. Consequently, commas are misused more than all the other marks combined. There are only four commas, which hardly seem a lot for such a difficult topic. Nevertheless, it is the four that get us all in trouble. The four types of commas are Omission, Bracket, Listing, and the Joiner.
That was simple. Now that you know their names, you know how to handle each one – right? Let’s make sure.
Let’s start with the Omission Comma.
True to its title, the omission comma replaces a missing word, most often “and.” The rule is – if you cannot put “and” before the word, then you should not use an Omission comma.
Example: As professors go, old man Jerkins is a boring, uninspired, tedious lecturer who will put you to sleep under two minutes.
You can change the above sentence simply by adding a “and” before “tedious lecturer” If you couldn’t put “and” before the word, then the comma is not needed.
Example: By removing one word, we render this sentence incorrect. “As professors go, old man Jerkins is a boring, uninspired, lecturer who will put you to sleep under two minutes.
“And” cannot be put in front of “lecturer,” therefore the use of the comma is incorrect. To make the sentence read right, we must put a comma before uninspired (it passes the “and” test) and a comma after “lecturer.” Example: “As professors go, old man Jerkins is a boring, uninspired lecturer, who will put you to sleep under two minutes.
Now why does this one little shift in comma placement work so well? Say hello to my little friend, the Joining Comma.
The joining comma joins independent clauses. The rule is each part of the sentence has to be able to stand by itself. Using the example above, we can remove the comma and rewrite the sentence to read: “As professors go, old man Jerkins is a boring, uninspired, lecturer. He will put you to sleep under two minutes. We had to add the subject “He” in order to link the professor back into the second sentence, but even without it, the assumptive subject would have still been the professor.
Be careful of joining commas, they tend to make run on sentences, they are hard to control, so that you feel like you are running out of breath when reading, like they will never end, never letting you stop long enough, and take one little breath.
Whew! Do you see what I mean? There are at least two separate sentences in the previous paragraph. Where would you place the period and start a new sentence? You could also use our little friend the listing comma to make the above sentence work. Let’s try it.
A listing comma is just as the name implies – it puts things in a series or list. For example: The attributes that make Joe Jones a good candidate for this position are punctuality, a stickler for details, professional leadership, a dedicated employee, and a inspiring team leader.
You can’t make these terms stand alone because the subject gets lost, so a “Joining” comma doesn’t work, and the commas are not “Omission” commas because if you put “and” in replacement of the commas, then the entire sentence becomes awkward and run on. Try it.
Two simple rules for listing commas. Rule 1: You have an option of placing a comma in front of the last item proceeding the “and” in the last item of a list. It is an option, and correct either way. The rule is – don’t let anyone chastise you for doing this – it’s his or her option as well.
Rule 2: Do not place a comma before the first item in the list, or after the last item in the list.
The Bracket (or parenthetical) Comma
The last in our series is the bracket comma. Also called the parenthetical comma it does what it says. It sets off a part of a sentence that contains information that may be nice, but not essential to that sentence. For example: In the development process of the widget, which will revolutionize the widget industry, we failed to estimate its greater value to tire manufacturers.
The bracket commas are separating a part of the sentence that, while informative, is not essential to making the sentence work, just like “which will revolutionize the widget industry” is not essential to making this sentence work. You could write the sentence: In determining the value of the micro widget (which will revolutionize the widget industry), we failed to realize its greater value to tire manufacturers. Here the information – while informative is not required. The subject is the micro widget and its value to tire manufactures.
The Final Word
As we can see here, the old rule of thumb of using a comma wherever you would take a breath, if you were speaking the sentence, is not entirely accurate. This rule of thumb does have some merit as a starting point, but it helps to know what type of comma is applicable when editing your work.