Pondering Punctuation: Demystifying the Comma, Part Five

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At long last, we’ve come to the final installment of our series on the correct use of the comma! If you missed any portions or would like to review, please see the list at the end of the post.

I have to admit that I’m suffering from a bit of comma burnout—and I’m sure you all are too! So let’s just dig in and get this done.

With Parenthetical and Descriptive Phrases

When your sentence contains a phrase that adds an explanation or comment, and you want to create the effect of just a slight pause, use commas to surround the phrase:

Using commas correctly can be, to say the least, confusing at times.

The use of periods, on the other hand, is usually straightforward.

If you remember back to our last installment, we talked a bit about essential and extra information. The distinction is important in comma usage because if a descriptive phrase is essential to identifying the person or thing it’s modifying, no commas are used:

The book with the distinctive blue cover is my favorite grammar reference.

Here the phrase with the distinctive blue cover is essential; if we removed it, a reader wouldn’t be able to tell which book we’re talking about: The book is my favorite grammar reference. Note also that there are no commas around the essential phrase.

But have a look at this sentence:

The Blue Book of Grammar and Punctuation, with its distinctive cover, is my favorite grammar reference.

Here, since we have the name of the book, the phrase with its distinctive cover is extra information. If we removed it, a reader would still know which book we’re talking about:  The Blue Book of Grammar and Punctuation is my favorite grammar reference. And note that we do need commas around the extra phrase. As we saw last time, you could think of the commas as miniature parentheses.  

(And by the way, The Blue Book of Grammar and Punctuation is a real book, and it is indeed one of my favorite grammar references. I highly recommend it! Note that I’m not an Amazon affiliate and do not receive anything for this endorsement.)

This rule—no commas for essential phrases, commas for extra phrases—also applies if the phrase starts with such as or including:

It’s best to avoid unusual words, such as multitudinous and deracinate, when writing for a general audience. 

Here the phrase such as multitudinous and deracinate is extra information, since we’ve already established that we’re talking about unusual words. The extra phrase merely supplies some examples, and it’s surrounded by commas. But if the sentence was written this way:

It’s best to avoid words such as multitudinous and deracinate when writing for a general audience.

In this sentence the phrase such as multitudinous and deracinate is essential for identifying what kind of words are to be avoided. If we removed the phrase—again, a good test to determine whether a phrase is essential or extra—we’d be left with the nonsensical It’s best to avoid words when writing for a general audience. Hmm, how would you do that? 😊 


With Dependent Clauses

Hooray, we’ve arrived at our final two comma rules! We have just one last grammar term to define quickly. In a previous post about colons and semicolons, we encountered the term “independent clause,” which means a clause that can stand on its own as a sentence. So if an independent clause can stand on its own, what do you think a dependent clause would be? Yup, it’s one that, even though it has a subject and a verb, can’t stand on its own as a sentence. For example:

*When I finish editing the book

*If there’s nothing that needs to be changed

These clauses clearly can’t stand on their own—they need another clause to round out the story. (The asterisk at the start means that they’re ungrammatical sentences.) Plumped out and paired up with a main clause, they might look like this:

When I finish editing the book, I’ll notify the author.

If there’s nothing that needs to be changed, the book will be published late this year.

And this shows the first dependent clause rule in action: when the dependent clause comes before the main clause, put a comma at the end of the dependent clause.

But what happens if we swap the order of the clauses?

I’ll notify the author when I finish editing the book.

The book will be published late this year if there’s nothing that needs to be changed.

Now the main clause is first and the dependent second, and there’s no comma. Most of the time this will hold true. There are only a few cases in which a comma might be necessary after the main clause:

  1. If there’s a significant contrast, indicated by the dependent clause starting with though, although, even though, or whereas;
  2. If the dependent clause starts with because and there is possibility of ambiguity (usually when the main clause contains a negative verb); or
  3. If the dependent clause is clearly parenthetical and has no effect on the overall meaning of the sentence.

Examples of these:

  1. The novel on the whole was good, although the end was a bit disappointing.
  2. Scott didn’t read the book, because his friends hadn’t liked it.
  3. I’ll finish up this post now, if you don’t mind.

If you’d like to read in more detail about these exceptional cases, check out this very thorough blog post. It’s written on a grammar nerd level of detail and so is not an easy read, but it does contain many good examples helpful for understanding these situations.

I hope that this series has cleared up at least some of the confusion you might have about the proper uses of the comma. But more importantly, I hope that you’ve come to realize that using commas—and in fact, all punctuation—is more of an art than a science. That’s why it’s so important to look for the rules in action when you read and to make a conscious effort to use them in your own writing. Remember that you can always send me your questions; I’m more than happy to help! Either post them below, or email to steph@tightprose.com.

And now, I promised you a recap of all the comma articles with links—here you go!

Part one: Commas in pairs; joining independent clauses; the serial, or “Oxford,” comma.

Part two: Commas with “not” phrases; with “the more…” “the less…” type phrases; with questions inside a sentence; with quotations; with parentheses.

Part three: Commas with introductory elements: words, short phrases, adverbial phrases, and participial phrases.

Part four: Commas with relative clauses and appositives—where the distinction between essential or extra information is particularly important.

Part five—this post: Commas with parenthetical and descriptive phrases, and with dependent clauses.

Pondering Punctuation: Demystifying the Comma, Part Four


One of the surprising side effects of the COVID-19 pandemic has been an increased demand for cybersecurity experts. It seems every time you turn on the TV lately, there are plenty of commercials offering programs to teach jobseekers these skills. Since we’re all online so much now—for work, shopping, and just staying in touch with each other—there’s increased risk of our personal data being stolen.

Have you ever stopped to think about what goes into that personal data? Just what information is essential to identify you as an individual? How about these: your full name; your birthday; credit card numbers; your Social Security number, for you Americans out there—the list is extensive, and even depends on the part of the word you live in.

But then there are other facts about you that, while interesting and maybe even important, are true of many people: that you live in a particular town or city; that you play a particular sport; that you have a dog or cat for a pet, and so on. This type of information doesn’t single you out; you could call it extra information.

In today’s installment of our continuing series on comma usage, let’s take a look at how these types of information—essential and extra—are handled in sentences.


With relative clauses:

A relative clause is a phrase within a sentence that modifies a noun and starts with that, which, or who/whom/whose. Sometimes a relative clause contains information essential to identifying a specific person or thing, but other times it contains extra information. For example:

When we visited the mother dog and her litter, we decided to take the puppy who had a white spot on her chest.

Our puppy, who has a white spot on her chest, loves to play fetch.

Notice how in the first example, the relative clause who had a white spot on her chest is essential for identifying which puppy we selected. If you got rid of that clause, the remaining sentence wouldn’t make any sense: *When we visited the dog and her litter, we decided to take the puppy. This leaves the reader wondering which puppy we picked. (BTW, the asterisk before the sentence means that it’s ungrammatical.)

In the second sentence, however, since we don’t have to single out a particular puppy, you could leave out the relative clause who has a white spot on her chest and the sentence would still make sense: Our puppy loves to play fetch. In this case, the clause who has a white spot on her chest is extra information.

Traditionally, grammarians have called the essential type “restrictive” and the extra type “non-restrictive.” But I’ve never found those terms helpful, so I’m going to stick with these concepts of essential and extra information throughout this post.

Now, on to the role of the comma. Look again at the essential example:

When we visited the mother dog and her litter, we decided to take the puppy who had a white spot on her chest.

Note that there is no comma before who. But in the extra example:

Our puppy, who has a white spot on her chest, loves to play fetch.

There are commas around the clause who has a white spot on her chest. So the rule is: if the relative clause contains essential information, it does not take commas; but if the relative clause contains extra information, it does take commas.

Another way to look at it is that the commas are functioning almost like parentheses—they are signposts that mean “We don’t need this information to identify someone or something.”

One more example:

Every book that Chuck owns is about sports.

The book The Boys of Summer, which Chuck owns, details the history of the early 1950s Brooklyn Dodgers.

If we remove the essential relative clause that Chuck owns from the first sentence, we’d be left with Every book is about sports. And of course that’s not true. Notice that there are no commas, either.

But we can remove the extra relative clause—everything between the commas—from the second and it’s still a true statement: The book The Boys of Summer details the history of the early 1950s Brooklyn Dodgers. The fact that Chuck has a copy of this book is extra information.

You’ve no doubt noticed that in the first sentence the word that starts off the relative clause, but in the second it’s which. You’ll come across some traditional grammars that prescribe using that only with essential clauses, and which only with extra clauses. But this is not actually a hard and fast rule. Native speakers of English tend to automatically use that only with essential clauses, but you can use which with either type. Just go with whichever sounds better to your ear, and then check whether you need to have commas (extra) or not (essential). Chances are that if you naturally used that, it will be an essential clause, which does not need the commas.


With appositives:

Whew! I know that was a lot to absorb. But fortunately this next rule works just like the one for relative clauses.  

First of all, what’s an appositive? It’s a word or phrase which usually follows directly after a noun and provides more information about that noun—for example:

Jason’s wife, Helga, is a German citizen.

Here Helga is an appositive to—more information about—Jason’s wife.

Do you see where we’re going with this? If an appositive provides more information about a noun, sometimes that information is going to be—you guessed it—essential, and other times it’s going to be extra. And the comma rules are exactly the same as with relative clauses: no commas with essential information; commas (again, think parentheses) with extra information.

So why did we use commas in that example? Jason has only one wife, so we don’t need her name to single her out. It’s extra information. But how about this one:

Jenn’s brother Nate came to visit her. 

No commas here—which means that Jenn has more than one brother; Nate is the one who came to visit, and his name is essential in order to pinpoint him. But what if the sentence had been written this way:

Jenn’s brother, Nate, came to visit her. 

At first glance this seems to be the exact same sentence. But check out the commas—this version means that Jenn has only one brother, so his name is extra information.

One more set of examples, this one not so tricky:

Many theater lovers consider Shakespeare’s play Hamlet the greatest drama of all time.

Beethoven’s only opera, Fidelio, is not often performed.

In the first sentence, Hamlet is essential to identify which one of Shakespeare’s plays we’re talking about—so no commas. But in the second sentence, since Beethoven wrote only one opera, the name isn’t essential—it’s extra information.

By now your head is probably spinning—mine certainly was when I first started paying attention to this distinction. And you might even wonder why it matters. I have no answer for that, other than to say that it does: observing the rules and correctly applying (or not applying) the commas will distinguish you as a careful writer who pays attention to detail.

And some good news—this is the most subtle, most difficult application of all of the comma rules. You’ve seen the worst now, so our last installment on the comma will be a piece of cake! I’ll be back soon with those few remaining rules. Until then, as always, look for these principles at work “in the wild,” and practice using them in your own writing. And please feel free to leave any questions below! 

Pondering Punctuation: Demystifying the Comma, Part Two

If you’re over the age of 45 or so, you might remember that back in the day the fast-food restaurant chain Wendy’s had several hilarious commercials containing the catchphrase “parts is parts.” Check out my favorite one of the bunch:

Unlike Wendy’s chicken sandwiches, however, many sentences are not one unbroken piece, but are made up of two or more parts. So in this installment of our continuing series on using commas correctly, let’s look at a variety of situations in which commas help mark off those parts.

With “not” phrases:

When you insert a phrase containing not to clarify a noun, set it off with commas (or just one if the phrase comes at the end of the sentence):

My friend likes mustard, not ketchup, on her burgers.

I prefer grilled chicken sandwiches, not the fried ones.

With “the more…,” “the less…” type phrases:

Usually you should place a comma between clauses (another term for phrases) that include constructions such as “the more…”, “the less…”:

Studies have proven what everyone suspects: the more fast food you eat, the more weight you tend to gain.

If the phrases are short, you may omit the comma (but it’s not wrong to still include it):

So the less you eat the better.

With questions inside a sentence:

If you want to include a question within a sentence in the form that it was originally asked—also known as a direct question—put a comma before it:

John asked himself, do I want a vanilla or a chocolate milkshake?

If the question is long or has its own internal punctuation, you may capitalize the first letter of the first word—but this is not mandatory:

The question on my mind was, Can those vegetable-based substitutes really fool people who love burgers made of meat?

But if you’re paraphrasing the question, that is, rewording it to make it indirect, then no comma or capitalization is necessary:

The question on my mind was whether those vegetable-based substitutes could really fool people who love burgers made of meat.

With quotations:

I think we all remember this one from school: when you introduce a quote in the middle or at the end a sentence, put a comma before the open quotation marks. This holds true whatever you’re quoting, whether it was written or spoken:

The newspaper’s food critic commented, “This new locally owned fast-food restaurant beats all the national chains hands down.”

Amy asked, “Are those chicken nuggets spicy?” 

But if you introduce the quotation with thatwhether, or a similar word, you don’t need the comma:

I assured her that “they’re not spicy at all.”

When the quote begins the sentence, place a comma at the end of the quoted part, just before the close quotation marks—unless the quotation needs a question mark or exclamation point:

“That was a good burger,” said Mark.

“I thought it was great!” exclaimed Dave.

With parentheses:

When you have material in parentheses that needs a comma afterwards—for example, it’s an item in a series—the comma goes outside the close parenthesis, never inside:

The order for the office included two chicken sandwiches, six burgers (four with cheese), and enough french fries for everyone.

I think that’s enough parts and commas for today, but I’ll be back soon with more. Most of these rules are pretty clear-cut, but please feel free to leave me a note below if you have any questions. The best way to start getting a handle on all these rules is to take them one at a time: choose just one and concentrate on it for several days in your writing. When you start feeling confident with that rule, take on another.  

And now I’ve gone and made myself hungry—time to get some lunch!