Comma use after the word but

If the clause after «but» has a subject and a verb, you need a comma before but. If the clause introduced by «but» does not have a subject in front of the second verb, the comma is often optional.

If the clause after «but» has a subject and a verb, you need a comma before but.

My sister loves cake, but she wants to avoid gaining weight.

My sister loves cake but she wants to avoid gaining weight.

If the clause introduced by «but» does not have a subject in front of the second verb, the comma is often optional. But you can use it to show more contrast or indicate a pause.

I love shopping but don’t have any money.

I love shopping, but don’t have any money.

1. Use a Comma to Introduce an Independent Clause

As a coordinating conjunction, but joins two clauses of a sentence. If the second clause can stand alone (it has a subject and a verb and forms a complete sentence), add a comma before but.

My brother loves watching TV, but he doesn’t like reading.

My brother loves watching TV but he doesn’t like reading.

Notice that both clauses on either side of the comma can stand alone.

Follow the same rules when using a comma before «and», «or», and other coordinating conjunctions such as «so», «for», «nor», or «yet».

My brother is an artist, and he loves painting.

My brother is an artist and he loves painting.

2. The Comma is Optional When Introducing a Dependent Clause

In some sentences, you don’t need to repeat the subject after but because it is the same in both clauses.

I understand Spanish but cannot speak it.

In the example above, «cannot speak it» is not an independent clause—it cannot stand alone. An independent clause needs a subject and a verb. In this situation, the comma before «but» is optional.

I understand Spanish, but cannot speak it.

Some writers minimize punctuation usage, while others prefer to use more commas to give readers a chance to pause and take a breath.

The classic Blue Book of Grammar and Punctuation argues that using a comma is generally unnecessary when the subject does not appear in front of the second verb.

❝ If the subject does not appear in front of the second verb, a comma is generally unnecessary. Example: Morty thought quickly but still did not answer correctly.❞

Kaufman, Lester; Straus, Jane. The Blue Book of Grammar and Punctuation.

Other authors, however, recommend using a comma if the conjunction is but:

❝ When the subject is the same for both clauses and is expressed only once, a comma is useful if the connective is but. When the connective is and, the comma should be omitted if the relation between the two statements is close or immediate. ❞

Strunk JR., William; White, E.B. The Elements of Style.

As a general rule, you can choose whether to include a comma before but after considering a range of factors, including clarity, emphasis, and rhythm. In any case, add a comma if it makes the sentence clearer.

3. Other Rules for Placing a Comma Before ‘But’

3.1 Use a comma if the clause does not limit or define

Insert a comma before «but» if the second clause does not limit or define; it merely adds something.⁽¹⁾

For example:

It is not very common, but certainly possible.

By saying «it is not very common», you are already implying that it is possible. Therefore, the phrase «certainly possible» does not limit or define. It just adds information to the main part of the sentence.

3.2 Add commas to set off expressions that interrupts the sentence flow

Use commas to set off expressions that interrupts the flow of a sentence.⁽¹⁾

I want to go, but not this year, to Italy.

I want to go but not this year to Italy.

3.3 Insert a comma before ‘but’ to separate contrasting parts of a sentence⁽¹⁾

For example:

The money is in your wallet, but it’s not yours.

4. More Examples

The second clause of these sentences are independent clauses; therefore, we place a comma before but:

• I tried to become a famous singer, but my father ruined it.
• It will be a painful process, but she has no other choice.
• I know it is expensive, but you have a lot of money.
• Yes, I know that you are tired, but you’re not finished.
• It sounds really interesting, but I have decided that I must decline your offer.
• John learns fast, but his attention span is very short.

These are some examples where the comma before but is optional:

• Yes, I have a lot of money, but not for your crazy ideas.
• They are working slowly but surely.
• I bought the car but can’t drive.
• Yes, I know that I am distracted, but cannot take my eyes off that girl when she’s talking.
• The food was good but not delicious.
• I would buy the red one but is too expensive.

5. Conclusion

Follow these guidelines to decide whether to use a comma before but:

1. Include a comma before «but» to introduce an independent clause.
2. If the subject does not appear in front of the second verb, the comma before «but» is optional.

6. References

(1) Kaufman, Lester; Straus, Jane. The Blue Book of Grammar and Punctuation. Chapter 2 (punctuation).

(2) Strunk JR., William; White, E.B. The Elements of Style.

Whether you should use a comma before or after but depends on the sentence construction. Recognizing the structure of a sentence will help you identify when you should use it. A few tips will make this task easy. But remember, there is always that pesky exception the rule.

Independent Clauses

Let’s begin with an example of a complete sentence.

• I want the cookies.

This simple string of words contains a subject, verb and object. It is also an independent clause. It can stand on its own without adding another word. Compare that one with another one.

• The store is closed.

It is also a complete sentence and an independent clause even though it doesn’t have an object as in the first example.

We can join the two clauses with a conjunction. These words function as joiners that link two sentences. They include words such as and, or and but. We can add a conjunction to our examples.

• I want the cookies, but the store is closed.
• He bought groceries, but he didn’t get any bread.

You’ll notice that we added a comma before but. That is because the two clauses are independent, making the comma necessary. You can test it by ending each clause with a period to see if it is a standalone sentence.

Dependent Clauses

With dependent clauses, these strings are not complete and cannot stand on their own. They include phrases missing a part of a complete sentence. We can join the two clauses with a conjunction.

• I want the cookies but forgot them.
• She was going to go the movie but stayed home to watch TV instead.

In this case, we didn’t add a comma because the phrase after but was a dependent clause. The bridge between the two clauses must be seamless, therefore, no comma before or after but.

What About Commas After But?

There is one situation in which you will find a comma after but. It occurs in cases where the writer makes a deliberate choice for literary effect. That’s where interrupters come into play.

An interrupter does just what the name implies. It breaks a sentence flow with a word, phrase or clause for effect. Here’s an example.

• But, if you must know the truth, I never owned a lead pipe or a candlestick.

The clause, if you must know the truth, stops the flow of the sentence to interject this point. As you can see, there is a comma after but. The punctuation with an interrupter is meant to offset it from the rest of the sentence. It will always have a comma before and after its placement to draw attention to its inclusion.

• Everyone was home, but, and this is important, no one heard him knocking at the door.

This goal of this sentence is to emphasize the unusual situation with an interrupter. In these cases, it’s helpful to understand the context to determine if the comma is necessary.

You should always use a comma before but when joining two independent clauses. A comma after but is only necessary if you’re using it as literary device to draw attention to something.

Updated 15 September, 2022: Do you struggle with deciding whether to use a comma every time you write but in a sentence? Well, let’s end the hesitation once and for all:

When Should You Put a Comma Before But?

This issue can be addressed with a simple rule: a comma should be used before but only when the conjunction is linking two independent clauses. For example:

RIGHT: I would go for a stroll, but the weather is terrible.

How do you know if a clause is independent? Well, let’s break it down. In a nutshell, you can think of a clause as a phrase containing a subject and a verb, and an independent clause is a phrase that makes sense on its own, while a dependant clause needs another phrase to make sense (its dependant on it). To figure out if a clause is independent or not, just follow these two steps:

1. Check the phrase that precedes the word “but:” I would go for a stroll.
2. Now check the phrase that follows “but:” the weather is terrible.

As you can see, both phrases make sense on their own, and can stand along as complete sentences. In this scenario, we have two independent clauses, therefore you must use a comma before “but.”  

When you don’t have independent clauses, leave the comma out.

WRONG: I would go for a stroll, but for the rain.

In this case, the conjunction is linking an independent clause to a dependent clause. You can tell this by looking at what is written after “but:” for the rain.

That phrase has no meaning on its own and can not stand as a complete sentence. Therefore it is a dependent clause. In this case, no comma is needed before the conjunction:

RIGHT: I would go for a stroll but for the rain.

Here are a few more examples

WRONG: The dog is only a puppy, but well trained.

RIGHT: The dog is only a puppy but well trained.

WRONG: Grammar is tedious, but necessary.

RIGHT: Grammar is tedious but necessary.

WRONG: The dog is only a puppy but he’s well trained.

RIGHT: The dog is only a puppy, but he’s well trained.

RIGHT: The car is old but fast 

WRONG: The car is old, but fast

The comma rule applies to the other conjunctions as well: and, or, and so.

Examples From Media Sources

Let’s take a look at a few real-life examples from reputable sources:

“Reached at their home in Southampton, N.Y., Mr. Dudley’s wife said that the passengers were “dear friends of ours” but that she did not know why they were flying from Manhattan.” – The New York Times

“It hopes the purging of Mr Ahern and others will save its skin, but the tribunal’s findings may stick.” – The Economist

When Do You Put a Comma After But?

If you are wondering whether a comma is need after the word but, chances are it is not.

You should only use a comma after but when the conjunction is immediately followed by an interrupter, i.e., a short word or phrase that interrupts a sentence to express emotion, tone, or emphasis.

REMEMBER: when there is an interrupter in the sentence, it must be preceded and followed by a comma. For example:

But, of course, it’s not prudent for Charlie to go outside on his own.

In the example above, of course is an interrupter. Even if you remove it, the entire sentence will not lose its meaning. The only reason it is added is to reinforce the statement.

If your sentence includes an interrupter directly after but, then you can use a comma. In all other cases, you will not need a comma after but.

Quiz

Now take this little quiz to test your newly found knowledge.  Add the commas in the sentences below

I wanted to repair the car but the shop was closed.
They spent the entire day on the boat fishing but didn’t catch any.
Mikhail had been warned about the dangerously cold water but would not stop swimming.
The house was for sale but the Hendersons could not come up with the downpayment.
She needed a way out of the situation but could not think of any.
He said he didn’t want any fires but of course, he regretted his decision the minute the food arrived.
His day was spent in isolation but for the occasional visit from the nurse.
There was nothing else to say but to go their separate ways.

Here are the answers:

I wanted to repair the car, but the shop was closed.
They spent the entire day on the boat fishing but didn’t catch any.
Mikhail had been warned about the dangerously cold water but would not stop swimming.
The house was for sale, but the Hendersons could not come up with the downpayment.
She needed a way out of the situation but could not think of any.
He said he didn’t want any fires, but, of course, he regretted his decision the minute the food arrived.
His day was spent in isolation but for the occasional visit from the nurse.
There was nothing else to say but to go their separate ways.

Further reading:

Is There A Comma Before “Which?”

“Serial Commas: Your Side, My Side and Their Side.”

Do You Put a Comma Before “Because?”