Commas After the Beginning of a Sentence

If you start a sentence with an introductory clause like this one, do you need to follow it with a comma? In formal writing can you ever use an introductory phrase without a comma?

Obviously the answer to both questions is yes. The real question is, Which sentence beginnings need commas and which don’t?

Dependent Clauses and Commas

When a sentence starts with a dependent clause, the clause should be followed by a comma. A dependent clause is a clause (i.e., it has a subject and a verb) that can’t stand alone as a sentence. It often starts with a word like if, because, until, or when (a.k.a. a subordinating conjunction).

• Until our enemies are defeated, we will continue to protect the castle.
• If Bao starts singing, everyone will join in.
• Because it was raining, Elphaba brought her umbrella.

When the dependent clause comes after the main clause, you don’t need to worry about a comma.

• We will continue to protect the castle until our enemies are defeated.
• Everyone will join in if Bao starts singing.
• Elphaba brought her umbrella because it was raining.

However, a comma is usual when the dependent clause doesn’t change the meaning of the main clause. (See That and Which for more on restrictive and nonrestrictive clauses.)

• We fought valiantly all day, until the sun set behind the hills.
• I’ll take a pass on the kale smoothie, if it’s all the same to you.
• Of course it was raining, because the universe hates me.

Participial Phrases and Commas

When a sentence begins with a participial phrase (a phrase starting with a participle, which usually ends in -ed or -ing), the phrase is generally followed by a comma.

• Exhausted from the gruelling flight, Nico hauled himself out of the airship.
• Knowing her cards were unbeatable, the dowager staked her entire fortune on one hand.

Commas are also used when the phrase occurs in the middle of the sentence.

• Nico, exhausted from the gruelling flight, hauled himself out of the airship.
• The dowager chuckled, knowing her cards were unbeatable, and staked her entire fortune on one hand.

However, you shouldn’t use a comma when the phrase changes the meaning of the rest of the sentence (i.e., when it’s a restrictive phrase).

• Nico always arrives exhausted from his gruelling flights.
• Knowing her cards were unbeatable was no reason for the dowager to stake her entire fortune on one hand.

Adverbial Phrases and Commas

An adverb tells you how, when, where, or why; an adverbial phrase is a phrase (a group of words that doesn’t qualify as a clause) that does the same thing. At the beginning of a sentence, these phrases can be followed by a comma, but they often go without—especially if they’re short.

• In 1918 Lu Xun published “A Madman’s Diary.” 
• Before the wedding Penelope plotted her revenge.

Do use a comma when it makes the sentence easier to read or when it prevents confusion.

• After days and weeks of incessant worry, we finally discovered our cat had been living at the neighbours’.
• For Clive, Owen was the ideal man.
• After eating, the rabbits we adopted were returned to their hutch.

It’s often helpful to use commas when the adverbial phrase appears in the middle of a sentence.

• We finally discovered, after days and weeks of incessant worry, that our cat had been living at the neighbours’.

But don’t use a comma when it’s at the end of a sentence …

• Lu Xun published “A Madman’s Diary” in 1918. 
• Penelope plotted her revenge before the wedding.

… unless the phrase doesn’t change the meaning of the sentence (i.e., it’s nonrestrictive).

• Lu Xun published “A Madman’s Diary” the following year, in 1918. 
• Penelope plotted her revenge that morning, before the wedding.

Introductory Interjections and Commas

An interjection at the beginning of a sentence is traditionally followed by a comma.

• Yes, it was a great day for disco. 
• No, that is not what I meant at all. 
• Well, it was the best we could do at the time. 
• Okay, that’s settled. 
• Oh, it was grand! 
• Ah, youth! 

But the comma is often omitted in informal contexts, dialogue, and common expressions.

• “No you don’t!”
• “Yes I will!”
• Oh my God!
• Oh yeah?
• Boy oh boy.
• Oh brother!

You can also use closing punctuation instead of a comma, turning your interjection into a one-word sentence.

• Well! What a shock!
• Oh? I stand corrected.
• Oh! I didn’t hear you come in.

There’s no particular phrase that is always—or never—followed by a comma: it all depends on the phrase’s function in the sentence. In this way commas point out a sentence’s structure. Readers subconsciously expect these flags, so using them consistently will make your prose easier to read. Of course, you can also choose to deploy an unexpected comma here and there, for dramatic effect.

Follow Grammarlandia on Facebook and never miss a post.

Go to Grammarlandia’s Patreon to become a supporter and receive access to bonus content.

That and Which

The choice between that and which can be confounding, especially if you include British usage (spoiler: the Brits use which in places where Americans insist on that). But before we can dive into the famous that/which rule, I need to introduce you to restrictive and nonrestrictive clauses.

Obligatory and Optional Phrases

A clause, phrase, or word is called restrictive when it’s necessary in order for the sentence to work. Take it out, and the sentence doesn’t convey the same thing.

• Animals such as bears should be treated with caution.
• People who jump queues should be strung up by their toes.
• The dragons fighting above my bed are keeping me awake.

Notice the lack of commas in these examples. Restrictive phrases are never set off with commas.

A clause, phrase, or word is called nonrestrictive when it’s not necessary for the sentence. You could take it out without losing any essential information.

• Hibernating animals, such as bears, should be treated with caution.
• Villanelle, who jumps queues, should be strung up by her toes.
• The castle’s pair of dragons, fighting above my bed, are keeping me awake.

Nonrestrictive phrases, unlike restrictive phrases, are set off with commas.

• The Earl, however, refused to be seen in a Volkswagen.
• The double-action shotgun, not diplomacy, was Anika’s forte.
• The giant Madagascar hissing cockroach, I understand, makes an affectionate pet.

Because of this, adding or deleting commas can change the information in a sentence.

• Her romance novel, Scottish Lords with Bulging Calf Muscles, is a bodice-ripper. 

Commas tell us the title is nonrestrictive: you could take it out and the sentence would say the same thing. Which means this is her only romance novel.

• Her romance novel Scottish Lords with Bulging Calf Muscles is a bodice-ripper. 

The absence of commas tells us the title is restrictive: without it we wouldn’t know which romance novel was meant. Which suggests she has written other romance novels, some of which may feature other kinds of lords with different muscles.

That said, the current preference among writers and editors seems to be for fewer commas, and as long as leaving out the commas isn’t likely to confuse the reader, then it’s acceptable to do so even with a nonrestrictive phrase. For example, if you leave out the commas around Myrna in my wife Myrna loves taxidermy, your readers probably won’t assume you have more than one wife.

On the other hand, if you’re writing about, say, siblings or offspring, you might want to use commas to show you only have one: our son, Xiaoping; my sister, Susan. (For more on this, see Commas, Names, and Chopsticks.)

That vs. Which

Understanding the difference between restrictive and nonrestrictive clauses is essential for choosing correctly between that and which. According to the that/which rule, that belongs in restrictive clauses and which belongs in nonrestrictive clauses.

• The UFO that arrived last week is still parked on our lawn. (Not to be confused with the UFO that arrived the week before.) 
• The UFO, which arrived last week, is still parked on our lawn. (Only one alien craft has ever landed here.)

In UK-style English, which is as likely to be used in a restrictive clause as that.

• UK: The dark cloud which hung over the mansion put a pall on their croquet game.
• US: The dark cloud that hung over the mansion put a pall on their croquet game.

But in any country, nonrestrictive clauses always use which.

• UK & US: The corpse, which was oddly familiar, gave Teuta pause.

Do You Need That That? 

The that in a restrictive clause can sometimes be left out if the meaning of the sentence is clear without it.

• Desta told him that it was time.
• Desta told him it was time.
• If I had known that the plant was carnivorous, I wouldn’t have bought it.
• If I had known the plant was carnivorous, I wouldn’t have bought it.
• Hari realized that that was the witch’s plan all along.
• Hari realized that was the witch’s plan all along.

Eliminating superfluous thats can make your writing cleaner and easier to read, which is why some editors insist on deleting the word wherever it turns up; however, there are places where a that is necessary for clarity.

• I learned when she took her camera I was not to follow. 
• I learned that when she took her camera I was not to follow. 
• I learned when she took her camera that I was not to follow.

It’s good to question your thats, because we often overuse them without realizing it, but don’t assume any that is a bad that.

In summary, use that when the clause is necessary to the sentence, and use which when it’s not. Unless you’re following UK style, in which case you can use which for necessary clauses too. But either way, when your clause is unnecessary, use which—and don’t forget the commas.

Follow me on Facebook.

Become a patron at patreon.com/grammarlandia and receive access to bonus content.

Comma Splices and How to Avoid Them

Like a botched Apparition spell, a comma splice happens when a comma is unequal to the task of carrying you from one clause to another.

Pierre snorted like a pig every time he laughed. He could hardly help it given his physiognomy.

• Pierre snorted like a pig every time he laughed, he could hardly help it given his physiognomy. X

A comma is not strong enough to join what would otherwise be two complete sentences.

• Pierre snorted like a pig every time he laughed. He could hardly help it given his physiognomy. ✓

A period is often the cleanest fix for a comma splice. There is nothing wrong with short sentences. However, if you want to convey a tighter relationship between your clauses—cause and effect, for example—you can use a coordinating conjunction, dash, colon, or semicolon instead.

• Pierre snorted like a pig every time he laughed, but he could hardly help it given his physiognomy.
• Pierre snorted like a pig every time he laughed—he could hardly help it given his physiognomy.
• Pierre snorted like a pig every time he laughed; he could hardly help it given his physiognomy.
• Pierre snorted like a pig every time he laughed: he could hardly help it given his physiognomy.

Demons have bad days like the rest of us, and sometimes they need a hug.

Coordinating Conjunctions

Coordinating conjunctions are the joining words and, or, but, so, yet, for, and nor. Using them makes the relationship between your clauses explicit, which is no bad thing.

• Demons have bad days like the rest of us, sometimes they need a hug. X
• Demons have bad days like the rest of us, and sometimes they need a hug. ✓

See Commas and Conjunctions for more.

Dashes

Dashes have a lot of uses, but in this case their interruption suggests an aside or a punchline, like an elbow to the ribs.

• Euphemia was a canny card sharp, even Death couldn’t beat her. X
• Euphemia was a canny card sharp—even Death couldn’t beat her. ✓

See How to Use Dashes for more.

Colons and Semicolons

Colons introduce, while semicolons join. Use a colon when the second clause explains or expands on the first. Otherwise, use a semicolon.

• Giacomo’s true nature was obvious in hindsight, he’d always avoided garlic, churches, and sunlight. X
• Giacomo’s true nature was obvious in hindsight: he’d always avoided garlic, churches, and sunlight. ✓ 
• It couldn’t have been easy, no wonder there were so few vampires in Italy. X
• It couldn’t have been easy; no wonder there were so few vampires in Italy. ✓

See Colon vs. Semicolon for more.

Euphemia was a canny card sharp—even Death couldn’t beat her.

All that said, if your clauses are very short, and if their structures match, you can get away with only a comma between them.

• I came, I saw, I conquered.
• Mum was in the orchestra, Dad in the ballet corps.
• She played, he danced.

What you don’t want to do is make your sentences flimsy paperclip chains of clauses hooked together by commas. Clarify your thoughts, then use the appropriate punctuation.

You can donate to this blog at patreon.com/grammarlandia.

Q&A: Parentheticals and Subject-Verb Agreement

What is the grammatical correctness for a sentence such as:

George Smith (and Tom Johanssen, of course) are making a strong contribution to the operations.

OR

George Smith (and Tom Johanssen, of course) is making a strong contribution to the operations.

The question really is: Is the information in brackets included in the grammar of the rest of the sentence or is it ignored?

George Smith (and Tom Johanssen, of course) is making a strong contribution to the operations.

The second version is the correct one: George Smith (and Tom Johanssen, of course) is making a strong contribution to the operations. As The Chicago Manual of Style points out, any matter set off with commas, dashes, or parentheses does not affect the rest of the sentence.

• Sarah, and of course her clones, has issues with authority.
• Cyril—and Gussie too—is excited about starting school in the fall.

If the correct version sounds awkward, try rearranging the sentence.

• Sarah and her clones have issues with authority.
• Cyril and Gussie are excited about starting school in the fall.

After all, correctness isn’t much good without clarity.

Cyril and Gussie are excited about starting school in the fall.

Become a Grammarlandia supporter on Patreon to keep this blog alive. You could have your question featured in a post.

How to Use Dashes

There are two kinds of dashes you’re likely to need in your writing—em dashes and en dashes. Neither is the same as a hyphen, so don’t think you can substitute without anyone noticing. An en dash is traditionally the length of a letter n, while em dashes are—you guessed it—the length of an M.

- hyphen
– en dash
— em dash

Cats make great roommates—if you don’t mind the smoking—and terrible landlords.

The Em Dash—An Interruption

The em dash is what most of us think of when we think of dashes—a break in the flow of the sentence. It’s often used as a colon, to introduce or expand on what came before (see Colon vs. Semicolon for more on colons), as in the last sentence and in this section’s heading.

Em dashes commonly work in pairs to set off a word or phrase from the rest of the sentence. They’re a little more emphatic than a pair of commas but a little less off-topic than parentheses.

• Cats make great roommates—if you don’t mind the smoking—and terrible landlords.

In dialogue, a pair of em dashes can make room for an action, and a single em dash can show interrupted or faltering speech. (For more examples, see How to Punctuate Dialogue.)

• “He said he’d be walking the thylacine”—Shareena checked her phone—“right about now.”
• “Whatever you do, don’t push that—”

Occasionally, an em dash follows a word or words that introduce a sentence’s main clause.

• Revenge—that was the sisters’ goal.
• Aliens, spaceships, face-eating fungi—nothing fazed Felipe.

Em dashes are often put before the source of a quotation, though they are not obligatory.

If you can’t say anything nice, come sit by me.

—Dorothy Parker

Revenge—that was the sisters’ goal.

The Dash With Other Punctuation

When a comma, semicolon, or period falls next to a dash, the dash shoulders it off the page. But when a pair of dashes encloses a phrase ending in an exclamation point or question mark, that punctuation can stay.

• Your combat skills are inferior—at least, inferior to mine—but your fashion sense is unrivalled. (No comma before but.)
• Spade unwrapped a black bird—could it be the Maltese falcon?—and casually set it on his desk.
• It’s not like I have a crush on him—as if!—but he does have nice hair.

The En Dash

En dashes are used to express ranges, where you might otherwise write from…to… or between…and…. They can also be used instead of to.

• The average human heart weighs 250–300 grams.
• Randy’s Roller Disco is open Tuesday–Sunday.
• Eartha Kitt played Catwoman in the 1967–68 season of Batman.
• The Rome–Sydney flight was cursed by a jet-lagged strega.
• Our impromptu game of “flaming quidditch” ended in a score of 7–3 and a visit to the ER.

What you don’t want to do is combine en dashes with from or between. Use words or dashes, not both.

• The Countess plans to travel incognito from April 6–May 12. X
• Emile and his imps serve coffee daily from 7:00 a.m. to 4:00 p.m. ✓
• Don’t go near the castle August–October. ✓

• Mastering spatula combat can take between 3–4 years. X
• Improving your diction will require between 10 and 15 marbles. ✓
• Each morning I believe 5–7 impossible things before breakfast. ✓

Eartha Kitt played Catwoman in the 1967–68 season of Batman.

Dashes, Typography, and Spacing

The equivalent of an em dash in typescript--in case you’re stranded on a desert island with only a typewriter--is two hyphens. As for en dashes, you can probably get away with using a hyphen instead—in fact, the Associated Press prefers it. However, there’s no reason to be old-fashioned when you have a computer at your disposal. Programs like Word automatically transform two hyphens--without spaces--into an em dash and a single hyphen - with spaces - into an en dash. (More on this below.) Since computers can’t always read your mind, it’s good to know the keyboard shortcuts:

Mac

En dash: Alt + Hyphen

Em dash: Alt + Shift + Hyphen

Windows (use numeric keypad)

En dash: Alt + 0150

Em dash: Alt + 0151

Should you put spaces around your dashes? Most American style guides, including The Chicago Manual of Style, prefer closed em dashes—that is, em dashes without spaces. But many British publishers use open en dashes – that is, en dashes with spaces – instead, and The Elements of Typographic Style considers the open en dash aesthetically superior to the em dash.

Though the closed em dash is more widely used, both are correct, so the choice is up to you. However, don’t put spaces around your en dashes when they are expressing ranges or to; such en dashes should always be closed.

Your combat skills are inferior—at least, inferior to mine—but your fashion sense is unrivalled.

A final word on dashes—try not to use too many. It may be tempting—they're so handy—but more than one or two per page—three at most—will look choppy and may distract your reader. I am, myself, occasionally guilty of overusing the dash. I have certainly done so in this post—purely for pedagogical purposes, of course.

When to Put Commas Between Adjectives

A conga line of adjectives sometimes (but not always) requires the intervention of commas to keep things straight.

Myfanwy’s dragon, Trevor, has multiple red heads.

In formal writing, coordinate adjectives—two or more adjectives that describe the same noun—should be separated by a comma. (Some people get a little carried away and put a comma before the noun too. These people are wrong. They deserve pity but not indulgence.)

• The demon made a dedicated, insinuating telemarketer.
• My ex is a low-down, no-good, lying rattlesnake.

However, sometimes two or more adjectives get by just fine with no commas at all.

• The only one who can safely walk the halls of the cursed high school is Sven, the janitor-ninja.
• Myfanwy’s dragon, Trevor, has multiple red heads.

How can you tell when your adjectives need a comma and when they don’t? Here are two helpful rules of thumb.

The Magic And

If you can put and between your adjectives, you should separate them with a comma. If and doesn’t sound right, no comma is needed.

• The demon made a dedicated and insinuating telemarketer. (✓ use comma)
• The only one who can safely walk the halls of the cursed and high school is Sven, the janitor-ninja. (X no comma)

The Adjective Switcheroo

Another approach is to swap your adjectives around. If your sentence still makes sense, use a comma. If not, leave it out.

• My ex is a lying, low-down, no-good rattlesnake. (✓ use commas)
• Myfanwy’s dragon, Trevor, has red multiple heads. (X no comma)

The only one who can safely walk the halls of the cursed high school is Sven, the janitor-ninja.

Why Adjectives Sometimes Don’t Need Commas

When one of the adjectives bonds with its noun to form a single idea, you don’t need to use a comma. Cursed describes “high school” as a unit, rather than the two adjectives cursed and high describing school. Similarly, multiple describes not just Trevor’s heads but his red heads.

• Janelle attended prom in a jet-black three-piece suit.
• Agnetha cannonballed into the dark blue depths of the space-time rift.

The colour jet black describes a three-piece suit, not a suit that happens to come in three pieces. In the second sentence, dark is describing blue, not depths. It’s acting as an adverb—describing an adjective—not a coordinate adjective.

• It was a cold winter morning on Venus.
• The Brontë sisters’ consumption worsened in cold, damp weather.

The first example shows us a winter morning that’s cold; winter is bonded with morning. The second example shows us weather that is both cold and damp, not damp weather that’s cold.

• That little old lady is a kung fu master.

Common expressions like “little old lady” or “big bad wolf” don’t take commas.

How Much Do We Need These Commas, Really?

These days, writers—especially those working in more informal genres—tend to use as few commas as possible. It’s not unusual in modern novels to see a long string of adjectives with nary a comma in sight. So, say you’re a twenty-first-century Faulkner: when do you really need a comma between adjectives? When it clarifies your meaning or amplifies your tone.

• The yeti was covered in matted white fur.
• The yeti was covered in white, matted fur.

The first sentence presents us with white fur that is matted, the second with fur that is both matted and white. The first reads more quickly and logically, giving us a whole picture, while the second draws our attention to the whiteness of the fur.

Notice that “matted and white fur” sounds weird, but “white and matted fur” doesn’t. That’s an indication that the second sentence needs a comma (remember, if you can put and between adjectives, you probably need a comma). Another way to think of it is that “white fur” is a recognizable idea, a kind of unit. “Matted fur” is just fur in an untidy state—a description of fur, not a thing in and of itself.

The yeti was covered in matted white fur.

• Imogen had a passionate, lifelong love of Marmite, despite its taste.
• Imogen had a passionate lifelong love of Marmite, despite its taste.

The first sentence implies a love that is both passionate and lifelong. The second implies a lifelong love that is passionate. Though the distinction is a subtle one, a writer might feel a strong preference for one version over the other, and their editor would be hard-pressed to say only one was correct.

• What a long, strange trip it’s been.
• Have you read Douglas Adams’s The Long Dark Tea-Time of the Soul?

In the first example, the Grateful Dead’s trip is both long and strange in equal measure, something emphasized by the comma. Adams could have chosen to write The Long, Dark Tea-Time of the Soul, but he may not have wanted a comma cluttering up his title. When there’s no possibility of reader confusion, whether or not to use a comma is often left to the author’s discretion.

Repeated Adjectives

There is, however, no authorial leeway when it comes to repeating the same adjective. Always separate these clones with commas.

• “My Love Is Like a Red, Red Rose” is by the Scottish poet Robert Burns.
• The movie It’s a Mad, Mad, Mad, Mad World was released in 1963.

The movie It’s a Mad, Mad, Mad, Mad World was released in 1963.

Commas are probably our language’s trickiest punctuation, but they’re worth the effort to master, if only for the sense of personal satisfaction, and the crowds of fawning groupies.

Commas and Conjunctions

A comma goes before words like and, but, and or—except when it doesn’t.

Have you made the appropriate sacrifices, or will you be leaving our fate up to luck or chance?

When And Needs a Comma

It’s traditional to put a comma before words such as and, but, or, so, and yet (a.k.a. coordinating conjunctions) when they’re joining two independent clauses. Independent clauses are clauses that could stand on their own as sentences if they wanted to. Think of them as train cars that could travel by themselves but have been hitched together to form one sentence.

• I’ve trained the squirrels outside my window to do backflips and pyramids, and we’ll be taking our act on the road next week.
• He bought the jester’s costume and the floppy hat, but I can’t help feeling his heart isn’t in it.
• Have you made the appropriate sacrifices, or will you be leaving our fate up to luck or chance?

If the sentence is quite short or its clauses are closely connected, you may leave out the comma.

• Mom played and Dad sang.
• The pirate queen unsheathed her cutlass and I knew it was over.

When But Doesn’t Need a Comma

Conjunctions don’t always join independent clauses—and they don’t always need commas.

• Clyde wanted to go to the orgy but couldn’t find any whipping cream.

“Couldn’t find any whipping cream” is not an independent clause: it lacks a subject and would never make it on its own as a complete sentence. Its subject, Clyde, is doing double duty for two verbs, wanted and couldn’t. (This is called a compound predicate, if you want to get fancy.)

• Clyde wanted to go to the orgy, but he couldn’t find any whipping cream.

Now each clause has both a subject and a verb, so our but can take a comma.

Similarly, when a single verb is shared between two subjects (called a compound subject), you don’t need a comma before the conjunction joining them together.

• Crawling up the side of a castle and crawling down the side of a castle are different levels of creepy.

As you can see, this rule applies to other conjunctions besides but.

• I knew the full moon was coming so didn’t bother to shave.
• He tried valiantly yet failed miserably.

I knew the full moon was coming so didn't bother to shave.

Parenthetical Ors

A comma might be found before an or or an and if it’s one of a pair enclosing an aside, or parenthetical phrase. These are phrases that are not essential to the sentence and could just as well be set between a pair of parentheses or dashes.

• Sook-Yin’s doppelgänger, or double, had been lurking in the lobby all week.
• If you know what I mean, and I think you do, give me a wink.

But with Not or Not Only

Constructions like “not only…but…” don’t take commas before the but.

• The cowboy was impressed not only by her hair but also her horns.

However, you may use a comma for emphasis if you choose.

• It would be not only his first trip to the Sierras, but his last.

The cowboy was impressed not only by her hair but also her horns.

Discretionary Commas: When to Break the Rules

Sometimes punctuation is as much an art as a science—particularly when it comes to commas. As in the case of the pirate queen earlier, it’s okay to ignore the “put a comma before a coordinating conjunction when it joins two independent clauses” rule if the clauses are short or tightly connected. You may even break up a compound predicate if you want to highlight the contrast between its verbs.

• The adventuress declared her eternal devotion to Alberto, yet left him to perish in the swamp.

Your most important consideration as a writer is clarity. An unconventional comma placement is sometimes necessary to keep readers from misunderstanding you. Notice how commas change the meanings of the following sentences:

• Jasika recognized the supervillain as he leaned out the porthole, and pointed an accusing finger.
• If you’re ready, and I think you’re up to it, you can dance the funky chicken at my bat mitzvah.

In creative writing and informal prose, commas are often discarded as a matter of style. It’s up to you as a writer to decide on the appropriate amount of punctuation for your piece. But before you can successfully flout the rules, you must understand exactly what you’re doing, and why.

Commas, Names, and Chopsticks

Should you put commas around a person’s name? Trick question! It depends on the sentence.

My sister Irina is the one with the absinthe habit.

In some cases, names should be held between a pair of commas like a piece of sushi between chopsticks; in others, commas are as superfluous and undesirable as a chaperone at an orgy. The difference is whether or not the name is needed to understand the sentence.

• The poet Yeats did not take rejection well.
• The next poet on the syllabus, Yeats, did not take rejection well.

In the first example, removing the name would change the sentence. “What poet?” we’d wonder. “Who are they talking about?” In the second example, taking out Yeats doesn’t change the meaning. We still know who’s being talked about—the next poet on the syllabus.

Commas go around a name when it can be picked up and removed from the sentence without changing its meaning.

• My sister Irina is the one with the limp and the absinthe habit.
• My sister, Irina, is the one with the limp and the absinthe habit.

Which sentence is correct? Both are, but they’re describing different situations. In the first, the speaker has more than one sister. Take out the name, and you won’t know which of her many booze-addled sisters she’s talking about. The name is essential, so it has no commas.

In the second sentence, the speaker has only one sister. Take out Irina and the sentence tells you the same thing it did before. The name is nonessential, so it’s set off with commas. The framing commas signal an interruption, a psst! What they contain is side business—informative, maybe, but not an integral part of the sentence.

• My werewolf, Duane, lives in the basement rec room.

This is fine if you only have one werewolf; his name can be removed from the sentence without changing its meaning. But what if you have a whole pack of werewolves stashed in your house? You need the word Duane so your reader won’t think you’re talking about your other werewolves, Geraldine, Wallace, and Leticia.

• My werewolf Duane lives in the basement rec room with the rest of his pack.

Disclaimer: Though this used to be a hard-and-fast rule, in The Chicago Manual of Style’s compilation of Q&As, But Can I Start a Sentence with “But”? (2016), the authors say these sorts of commas are now optional where the meaning is obvious. So, for example, you may write “my husband Hieronymus is a painter” without fear that your readers will assume you have more than one husband.

Job Titles and Commas

Unnecessary commas like to creep in when a name follows a job title or description, but you can weed out the extras using the same principle as above.

• Loyalist Spies and Their Lizards was written by renowned historian and amateur herpetologist Elena Gutierrez.

Without the name we are left scratching our heads and wondering “Who? Which historian/reptile enthusiast can they mean?” Her name is essential, therefore comma-less.

• Loyalist Spies and Their Lizards was written by Belleville’s own renowned historian and amateur herpetologist, Elena Gutierrez.

Belleville can boast only one historian and herpetologist, so even without her name we’d still know who’s being referred to. Since the name can be plucked out without changing the sentence, it is set apart with a comma.

• Chartered accountant Neville Wimsey dreamed of being a lion tamer.
• Our company’s chartered accountant, Neville Wimsey, dreamed of being a lion tamer.

Direct Address Loves Commas

Another situation in which names need commas is when you are speaking to someone directly.

• Fatima, I don’t think you understand what this eggplant means to me.
• Dammit, Jim, I’m a doctor, not a go-go dancer!

Grab a flamingo, everyone!

Such names are always set off with commas—even when they’re not actually names:

• Death, where is thy sting?
• Grab a flamingo, everyone, and start playing!

In fact, the chopsticks-and-sushi rule can apply to all kinds of words and phrases. This is where grammar nerds like to throw around the terms restrictive clause and nonrestrictive clause, meaning words that are essential to the sentence and words that are not. But I’ll save more on that for a later post. In the meantime, reader, pick up your commas and dig in!