Here is My Poem About a Certain Punctuation Mark (you know who you are)

Comma Chameleon
A Love Poem
By Peggy Anne

Sadly undervalued in punctuation fandom
Is the comma, the use of which can sometimes seem quite random.
In fact, the poor comma is tragically constricted;
Its placement and effects are by rigid rules restricted.

Rule 1: The comma precedes a conjunction
Connecting two independent phrases, each of which as a sentence on its own could function.
“This Sunday morning the sun is shining,
but it’s Super Bowl day, so I’ll soon be whining.”

Rule 2: Use a comma with yet, for, and so
As in the silly sentence that I’ve written below.
“I fear I am under some devilish curse,
For my poetry’s going from bad to verse.”

Here I must warn of a serious vice—
A comma wedged between two independent phrases sans conjunction (and, but, or, nor) creates a hideous comma splice.
“I could’ve been a glamorous and wealthy movie star, I didn’t learn my commas and so this is where I are.”

Rule 3: The comma separates items in a series,
Whether words or phrases or even plaintive queries.
“Am I lost, or confused, or all of the above?
Is this simple indigestion, or bad cheesecake, or love?”

Between two adjectives, the comma forms a fence
But only if reversing them does not spoil the sense.
“The hairless, pink rat was really very sweet,
Even though the pink, hairless rat had disturbingly hairless feet.”

Rule 4, in which the comma sets off an introductory phrase
Can be tough to remember--but remembering this rule pays.
“When hunting werewolves, you should always bring candy.”
To test, transpose the clauses to see if the sentence still lives, as in: “You should always bring candy when hunting werewolves.” This trick can come in handy.

Rule 5: Commas surround parenthetical elements
That provide secondary information about, but do not greatly change the meaning of, the sentence.
The sentence above serves as its own illustration
Of a “parenthetical phrase set off by commas” situation.

Rule 6 has to do with modifiers nonrestrictive;
Bracket them with commas, be they factual or fictive.
“The werewolf, who once kissed a cousin of Kevin Bacon,
Was not really hurt; he was obviously fakin’.”

If a phrase modifies in a manner restrictive
Unto that phrase, no commas do we give.
“The werewolf who was standing by the door
Was not related to the werewolf who was bleeding on the floor.”

Finally, Rule 7 is a kind of laundry list
Of sundry comma uses that we otherwise have missed.
It separates a quote from the phrase identifying the speaker.
“Gert said, ‘You may be strong, but you’re a bully, and I shall inherit the earth as the meeker.’”

A comma should also be used
To prevent geographic units from being punctuationally fused.
“Fargo, North Dakota, on the map is just a blip.”
(Leave the comma out between a state name and a zip.)

If giving month-day-year, commas are appropriate;
With day-month-year format, the commas we omit.
“My students think from the slime I crawled in December, 1792.
On 18 December ‘92, I was born to a monkey in the Zanzibar zoo.”

Put a comma before a title or degree
As in: “Elmer Livingston Fudd, M.B.A., Ph.D.”
Don’t use the comma if the other way round,
As in: “Dr. Livingston, is it you I have found?”

Everyone knows that when writing numerically
Commas show increments of thousands, no matter how stratospherically.
Finally, the crucial rule (the end is drawing near!):
If your meaning is ambiguous, use a comma to make it clear.