From Writers in the Storm:
Welcome to comma central, where we’re talking about all things comma. Among most writers, you’ll find a consensus when it comes to this tiny, ambiguous mark. They don’t like it. It’s too confusing. When do you use it? Where do you use it? Why do you use it? And who even cares, really?
Trust me, as a writer, you do!
. . . .
In this section, we’ll cover essential and nonessential information in a sentence and how that plays into when and where you add in commas or leave them out.
But first, a quick review.
A CLAUSE is a group of words with a subject and predicate that make up part of a complex or compound sentence.
Or think of it this way. A CLAUSE has both a noun and a verb and is part of a longer sentence.
A SUBJECT is a noun (person, place, thing) doing the action.
A PREDICATE is a verb that tells you what action that noun is doing.
An OBJECT is a noun (person, place, thing) receiving the action. Not all sentences have objects, and that’s okay.
Here’s an example.
Mr. Jones (noun) walked (verb) his yippy dog (object) at the crack of dawn.
Nonessential vs Essential Information
When it comes to your sentence, what information can you afford to lose and what information do you have to keep? How do you figure it out? And what do you do once you know?
The quick answer is:
- nonessential information is the part of a sentence you can do without.
- essential information is the part of a sentence you can’t do without.
Let’s start with nonessential information—the parts of a sentence you can do without. That doesn’t mean we’re putting those words on the chopping block. It just means we need to set them off with commas.
What we put inside commas or after a comma is usually considered NONESSENTIAL information. It isn’t needed to decipher the meaning of the sentence.
In the examples below, the bolded words are nonessential.
Inside Commas: The book on the shelf, which is exciting, is the one you should read next.
After a Comma: The weather in Texas is hot, which I really don’t like.
Do you see how the bolded information doesn’t really matter when it comes to understanding the sentence? The important part the author is trying to get across is that it’s hot in Texas.
The key point to note here is this. If we were to take out anything between the commas or after the comma, the sentence still has to be grammatically correct and make sense. It has to do both.
Nonessential words are red shirts. Like in the original Star Trek. Treat what’s in between commas of after a comma as a red shirt—an expendable part of the team, usually the first to die. At any time, I could sacrifice it without losing a crucial member of the sentence squad.
Inside Commas: A week off for vacation, I think, is great.
After a Comma: A week off for vacation is great, I think.
Removing “I think” in either instance above changes nothing grammatically or in terms of what each sentence means.
The red-shirt idea works for clauses, phrases, and single words too. Any of the words in bold below can be deleted and still keep the sentence grammatically correct without changing the essence of what I want the sentence to mean.
- Clause: Next October, which is my favorite month, works for our writing retreat.
- Phrase: You’re a great guy. Your brother, sad to say, I could do without.
- Word: I usually like my English teacher. Today, however, I do not.
Link to the rest at Writers in the Storm