How is it that such a tiny mark in our English language can cause so much confusion? Today I’d like to take a closer look at the proper use of commas as well as an improper use in hopes to eliminate some of that confusion. Here are just a few do’s and dont’s of commas usage:
1. Do use a comma to introduce a quote: He said, “Let’s go to dinner.”
Do not use a comma to introduce a maxim or proverb: The phrase “In God we trust” can be found on our money.
2. If a comma is needed in a sentence with a parenthetical phrase, it always goes after the closing parenthesis:
Be sure to bring food, a sleeping bag, a coat (if it’s cold outside), and a flashlight to the campsite.
3. Always use a comma before and after a state or country name if a city name immediately precedes it: I was born in Cincinnati, Ohio, but have lived in many other places.
4. Do use a comma after an introductory phrase: Before leaving on the plane, the passengers were thoroughly searched. Exceptions to this include very short introductory phrases as well as those cases where there would be no misreading of the sentence if there wasn’t one.
Do not use a comma for introductory phrases that are immediately followed by a verb: Before the doorway stood a looming figure.
5. Do use a comma with coordinate adjectives, which are adjectives that can be reversed in order and can be joined by the word and and still make sense: It was a very dry, cold winter.
Do not use a comma with adjectives that cannot be reversed in order or that no longer make sense when joined with and: She word a long yellow dress.
6. Do use a comma to set off a non-restrictive word or phrase (one that can be omitted without causing confusion about the noun it refers to): My husband, Derrick, is a personal trainer. Note: One way to test this is to ask, Is the word or phrase one of a kind? So, in this sentence, since you can assume I only have one husband, commas would be used to set off Derrick.
Do not use a comma where the word or phrase is restrictive: His book Tall Tales was a bestseller.
In this sentence, the reader would have to assume that the author has written more than one book since there are no commas to set off the title of the book, which in this case is a restrictive phrase. However, if he had written only one book, the sentence would read: His book, Tall Tales, was a bestseller.
7. Do use a comma to set off any non-restrictive relative clause, which is followed by the words which or some form of who: I ate breakfast, which consisted of eggs, toast, and sausage. Again, a non-restrictive clause is one that can be eliminated without changing the meaning of the rest of the sentence.
Do not use a comma to set off restrictive clauses, which are preceded by the word that and which would change the meaning of the sentence if eliminated:
The breakfast that I ate consisted of eggs, toast, and sausage.
Those are but a few of the many, many rules governing comma usage. I would offer a few more, but too much talk of commas may send one into a coma!