Commas, Part 6

Commas, Part 1
Commas, Part 2
Commas, Part 3
Commas, Part 4
Commas, Part 5

Once you're through today's discussion, you're halfway done with this 12-part series!

Today, we talk about commas and parenthetical expressions. Let's start with the latter before we talk about the former. What is a parenthetical expression?

Sometimes just called a parenthetical or even a parenthetic, a parenthetical expression is a group of words—walled off by commas, em dashes, or parentheses—that adds nonessential information to a sentence. There are different reasons to wall off words in this way: to make the reader privy to an aside, to emphasize an idea, to add a bit of drama, etc. Parentheticals are often associated with appositives, i.e., words or phrases that identify a noun, acting like adjectives. When the appositive contains essential information, no commas are needed. When the information is nonessential, you surround the appositive with commas... and a parenthetical is born. (In other words, as mentioned above, no parenthetical will never contain essential information! This is good to remember. Strip a parenthetical out of a sentence, and the sentence's essence remains.)

Here are some appositives that are also parentheticals:

• Sheila, the boss's wife, was the wank fantasy of every guy in the office.
• Principal Simmons, the family cat, loved burying his face in tuna.
• Phil McKraken, the banana-stealing macaque, was about to get his comeuppance.
• Superman (that horny bastard) face-raped a marble statue of Jefferson Davis.

As for the punctuation: em dashes make for more dramatic parentheticals. Compare:

• The reason you felt nothing was that Dr. Trump used his hands—not his penis—to probe your tonsils.
• The reason you felt nothing was that Dr. Trump used his hands, not his penis, to probe your tonsils.

Parentheticals can appear at the beginning and at the end of sentences. In such cases, only one em dash or one comma will be necessary. To wit:
• In the beginning, the cosmos was a giant wormhole called The Great Fallopian.
• Crotch-scratching Marvin was a virgin—or so the legends said.

IMPORTANT: remember that a parenthetical doesn't count when you're considering subject-verb agreement. Look at the following examples to see what I mean:
• Sam's dick—and his balls, too, for that matter—was covered with claw marks.
• Claudia, and also her loopy sister Olga, claims to have impregnated a giraffe.

In each of the two sentences above, I've bolded the simple subject and the simple predicate so you can see the subject-verb agreement in action. In the second sentence, you might be sorely tempted to treat the parenthetical as part of a compound subject, but this is not the case.

NOT COMPOUND: Jim, as well as his dog Lassie, has an unhealthy fascination with sheep.
COMPOUND: Jim and his dog Lassie have an unhealthy fascination with sheep.

Introductory expressions, which we already talked about in Part 1, are arguably a type of parenthetical.
• Five years ago, I unleashed a fart that moved California a meter to the west.
• To Hilda's great shame, Torrance the bulldog had defecated yet another pentagram.

To sum up: parentheticals are usually marked by commas, em dashes, and parentheses. They normally contain nonessential information, and you shouldn't consider them when trying to figure out subject-verb agreement. Introductory expressions and appositives can also be parentheticals. When parentheticals appear at the beginning or the end of a sentence, they are marked off by only one comma or em dash, not by a pair of either.

We good?

QUIZ
In the comments section or on a different writing surface, rewrite the following sentences with commas if needed. Also, correct any incorrect grammar. Do not rewrite if there's nothing to correct. Highlight the space between the brackets to see the correct answers.

1. Nancy Pelosi no stranger to adversity gamely kayaked along a river of mucus on her way to the main river of hell.
2. Confident in his own abilities Max dramatically removed his codpiece and ordered Charlotte to fire the bean-bag gun at his crotch.
3. The elf who saw Santa naked was immediately struck blind and afflicted with leprosy.
4. The Yorithra a dreadnaught-class battle cruiser searched the vast Deferens Nebula for the last remaining Scroton ship.
5. Silas's cat and also his dog scampered over with Silas's wife's eyeballs in their mouths.
6. Pastor Bowers and maybe his nephew as well were presumed eaten by a gay anaconda.

ANSWERS
[1. Nancy Pelosi, no stranger to adversity, gamely kayaked along a river of mucus on her way to the main river of hell.
2. Confident in his own abilities, Max dramatically removed his codpiece and ordered Charlotte to fire the bean-bag gun at his crotch.
3. NO CHANGES NEEDED.
4. The Yorithra, a dreadnaught-class battle cruiser, searched the vast Deferens Nebula for the last remaining Scroton ship.
5. Silas's cat, and also his dog, scampered over with Silas's wife's eyeballs in their mouths.
6. Pastor Bowers, and maybe his nephew as well, was presumed eaten by a gay anaconda.]