There are some comma rules that shouldn’t be broken. Doing so will make your prose sound tinny or not well crafted. Other times a misplaced comma might be the oomph your sentence needs to make it ring. Properly placed commas show mastery while too many commas placed wherever an author feels one should go, scream of unprofessionalism.
For the next few weeks, let’s talk commas. Learning a few each week and applying them to your manuscript or editing with an eye toward proper placement will help to re-enforce these rules.
Comma Rule 1: Two main ideas (or independent statements), which can stand alone and are connected by a coordinate conjunction, need a comma before the conjunction.
Example: John wanted to learn about commas, but Mary decided it was a waste of time.
When either sentence is a dependent clause (can’t stand alone), the comma is not utilized.
Example: John had wanted to learn about commas but decided it was a waste of time.
The word so when used alone is a coordinate conjunction, and when placed between two independent statements, it requires a comma. Add the word that and a comma is no longer necessary.
Comma Rule 2: When contrast is made in a sentence by the use of a pair of coordinates, a comma is not used.
Example: Neither Jane nor John wanted to take the time to learn the rules of comma placement.
Comma Rule 3: When lengthy introductory phrases (with grammatical names we will not go into now) are utilized before the introduction of the main idea, a comma is utilized to set off that phrase from the main idea. A short introductory phrase may also require a comma depending upon the clarity of the sentence.
Example: If I don’t master the rules of punctuation, how will I know when to break them?
Note: If the sentence is changed, and the introductory clause is moved to the end of the sentence, a comma is not utilized.
Example: How will I know when to break them if I don’t master the rules of punctuation?
Comma Rule 4: When a sentence has a series of three or more, a comma is utilized.
Mary bought a book on grammar, a tutorial on punctuation, and a DVD on writing with style.
Note that a comma is included before the word and. Also, care should be used when the sentence includes two words that naturally flow together.
Example: John decided he wanted food and purchased macaroni and cheese, pork and beans, and a chocolate brownie.
Comma Rule 5: A comma is used to separate information not necessary in understanding a sentence.
Example: Mary, a writer, loves grammar.
However, if the information is necessary to the sentence, the comma is not utilized.
Example: That man who never read a book knows more rules of grammar than John or Mary. [The who never read a book can be omitted, but the impact of the sentence would not be the same.]
In the same way, a word or group of words that adds meaning to the main idea but is not necessary, should be offset by commas.
Example: John, Mary’s friend, drove her to the bookstore.
Reword the sentence and a comma is not utilized.
Example: Mary’s friend John drove her to the bookstore.
However, if John is Mary’s only friend, you will want to utilize the commas around his name to distinguish him as such.
Next week we’ll cover more of the rules regarding commas. Until then,