Critical Thinking: Commas!

Guest columnist
Sarah Pottenger

---

COMMAS!

You know how if you stare at a word long enough, it stops looking real? Well, you're going to see the word “comma” so much in this article that it'll seem like a term out of a sci-fi story. But you'll get some education along the way.

It has come to my attention that there is a widespread epidemic of comma misuse. Since there is no rhyme or reason to it, I saw the need for a comprehensive article on when and how to use commas.

(In case you're interested, I'm drawing from the book Rules for Writers, by Diana Hacker. If you struggle at all with the technical side of writing, I strongly suggest you peruse HyperGrammar.com and/or consider picking up a grammar handbook.)

Why Do We Need Commas?

Punctuation = clarity. Commas (and other punctuation) are clues to the reader as to how each sentence is to be read and what each sentence means. Without commas, parts of a sentence can crash into each other, which leads to misunderstandings.

Confusing: If you cook Sarah will do the dishes.
Confusing: While we were eating a mountain lion approached our campsite.

If you add commas in the correct places, the meaning becomes clear. Sarah is no longer being cooked, and no one is eating the mountain lion.

Rule #1: The Conjunction Rule

Use a comma BEFORE a coordinating conjunction joining independent clauses.

When a coordinating conjunction connects two or more independent clauses—word groups that could stand alone as separate sentences—a comma must precede it. There are seven coordinating conjunctions in English: and, but, or, nor, for, so, and yet.

Example: Her name is Rebekah, but everyone calls her Fern.

Exception: If the two independent clauses are short (that's both of them, everyone) and there is no danger of misreading, the comma may be omitted.

Example: The plane took off and we were on our way.

Do NOT uses a comma to separate coordinate word groups that are NOT independent clauses.

Example: Part of my job is to teach you how to write better and follow rules.

Rule #2: The Introductory Rule

Use a comma after an introductory clause or phrase.

The most common introductory word groups are clauses and phrases functioning as adverbs—telling when, where, how, why, or under what conditions the main action of the sentence occurred.

Example: When David was ready to eat, his bird jumped onto the table.

Without the comma, readers may have David eating his bird. The comma signals that his bird is the subject of a new clause, not part of the introductory one.

Exception: The comma may be omitted after a short adverb clause or phrase if there is no danger of misreading.

Example: In no time Jessica reached the end.

Sentences also frequently begin with phrases describing the noun or pronoun immediately following them. The comma tells readers that they are about to learn the identity of the person or thing described; therefore, the comma is usually required even when the phrase is short.

Example: Knowing that she couldn't outrun a car, Elsie took to the fields.
Example: Excited about the move, Nikki began packing her books.

The commas tell readers that they are about to hear the nouns described: Elsie and Nikki.

Rule #3: The Series Rule

Use a comma between all items in a series.

When three or more items are presented in a series, those items should be separated from one another with commas.

Example: At the Shafers', one can order fillet of rattlesnake, bison burgers, or pickled eel.

Although some writers view the comma between the last two items as optional, most experts advise using the comma because leaving it out can result in ambiguity or confusion.

Example: Kate willed me all of her property, books and costumes.
Kate willed me all of her property, books, and costumes.

Did Kate will her property and her books and her costumes—or simply her property, consisting of books and costumes? If the former meaning is intended, a comma is necessary to prevent confusion.

Rule #4: The Adjective Rule

Use a comma between coordinate adjectives not joined by and.

When two or more adjectives each modify a noun separately, they are coordinate.

Example: As she gets older, Leah is becoming a strong, confident, independent woman.

Adjectives are coordinate if they can be joined with and (strong and confident and independent) or if they can be scrambled (an independent, strong, confident woman).

Adjectives that do not modify the noun separately are cumulative, and no commas are used between them.

Example: Three large gray shapes moved slowly toward Amanda.

You can't insert the word and between cumulative adjectives (three and large and gray shapes). Nor can you scramble them (gray three large shapes).

Example of Coordinate Adjectives: Jordan is a warm, gentle, affectionate person.
Example of Cumulative Adjectives: Michelle ordered a rich chocolate layer cake.


Next week: More Commas!

---

While Kersley is not licensed to use commas without direct adult supervision, Sarah Pottenger is. She is a long-time mentor at the teen writer's forum The Clean Place, a five-time winner of NaNoWriMo, a sci fi fan and writer, and a hater of peas. This article first appeared on The Clean Place.