Don't tell us punctuation challenged there are five rules for commas and then just run off into the forest!
Sorry. No one's asked before.
Rules and a few examples:
For U.S. publications, five rules explain necessary commas. A few other commas are optional, but the majority are superfluous—excessive, pointless, unnecessary.
Comma Rule Number 1: A comma is necessary to separate a compound structure, two or more main clauses joined by one of the seven coordinating conjunctions: and, or, nor, but, for, yet, so.
The woman drank black coffee, and she ate a croissant.
You can conduct yourself in a pleasant manner, or you can be horrible.
Evan loves Suzanne, but he cannot forget Elena.
If a writer chooses to make those constructions into simple sentences, then the comma is not used:
The woman drank black coffee and ate a croissant.
You can conduct yourself in a pleasant manner or be horrible.
Evan loves Suzanne but cannot forget Elena.
Comma Rule Number 2: A comma is necessary to separate a long introductory element before a main clause. Rule 2 holds true for both simple and complex constructions:
Even though ignorant of our culture, we must always be kind to strangers. (Simple)
Since Constance is new to our company, all of us should strive to help her. (Complex)
It’s always correct to set off any introductory element with a comma, but a more modern lean toward fewer commas in novels has made the practice optional for shorter elements. Either is acceptable:
Later, you can join us for dessert.
Later you can join us for dessert.
Comma Rule Number 3: Commas separate items in a series:
James found blondes attractive, redheads adorable, and brunettes irresistible.
The final comma before the conjunction is always correct. However, the journalistic practice to omit the serial (or Oxford) comma is every author’s option:
James found blondes attractive, redheads adorable and brunettes irresistible.
Also correct is an occasional asyndeton, the intentional omission of the normally occurring conjunction (
and, or, nor, but, for, yet, so) in a series of words, phrases, or clauses:
James found blondes attractive, redheads adorable, brunettes irresistible.
Comma Rule Number 4: Interjections and forms of address are set off with commas.
Yes, I will accompany you to the ball.
No, I won’t!
You, sir, are out of line.
You may be assured, ma’am, of our concern.
Are you certain of that prognosis, Doctor?
Thank you, Mother, for all you do.
There’s a world of difference between “Let’s eat, Grandpa” and “Let’s eat Grandpa.”
Comma Rule Number 5: Words, phrases, or clauses (appositives and infinitives included) which interrupt the main clause must be set off with commas fore and aft. The rule includes the state following the name of a city and the year following the day of the month.
Mrs. Ellen Bennet, my mother, is in the drawing room.
The Brooklyn Bridge, as opposed to this matchstick construction, is sturdy and reliable.
He was born on June 23, 1941, near Big Timber, Montana, along the Yellowstone River.
Those earrings, in my opinion, would look better hanging over formal dining tables.
5A. The final necessary use of the comma is the most difficult for many writers. It’s actually the same as rule 5, but it’s often presented in isolation because of its difficulty. As with appositives and infinitive phrases, it separates nonrestrictive clauses in a sentence. The nonrestrictive clause is not essential to the sentence. It merely adds information:
Abraham Lincoln, who was the tallest of U.S. presidents, was an imposing figure of a man.
The grizzly, a bear misunderstood by tourists, is named Ursus horribilis for good reason.
By contrast, a restrictive clause is essential to the sentence:
The lady who cried is my mother.
The man who shot Liberty Valance became a state senator.
