What is a comma splice?

A comma splice is a type of error that occurs in the English language when two independent clauses are joined together without a proper conjunction. This results in a run-on sentence.

Comma splices are relatively common punctuation errors, but they are easy to fix once you know what to look for.

In this guide, we'll cover:

• What is a comma splice (with detailed examples)
• How to fix a comma splice
• Some more comma splice examples
• When you can use a comma splice
• Some grammatical jargon you should know

Learn more about when to use a comma.

Publish stunning, interactive web content for free with Shorthand.

No code, no credit card, and no commitment required.
Get started.

A comma splice is a type of run-on sentence that joins two independent clauses together, often with the use of a comma. An independent clause is a clause that could stand on its own as a complete sentence.

Most often, a comma splice occurs when the writer forgets to use a conjunction (like and or but) to link a second independent clause.

Comma splices also arise when the writer uses a conjunctive adverb — like 'however, nevertheless, furthermore, and moreover — and forgets to add proper punctuation marks.

While a comma splice is technically considered a grammatical error, it is sometimes used for effect in writing. When used intentionally, a comma splice can create a choppier, more staccato-like sentence that can help to add emphasis or drama. However, if you are not careful, a comma splice can make your writing sound sloppy, so it is generally best to avoid them unless you are intentional about using one.

If you want to avoid comma splices in your writing, there are a few different options. You can use a semicolon to join the two independent clauses, or you can insert a conjunction. You can also split the sentence into two separate sentences.

In addition to comma splices, there are a few other types of errors that can occur when joining two clauses together. These include run-ons, fused sentences, and subject-verb agreement errors.

Looking to create visual content? Learn how to get started with our top 8 visual storytelling tips.

Example comma splice #1

Here is an example of a comma splice error:

The cat slept through the storm, it was unbothered by the thunder and lightning.

This sentence contains two independent clauses: "The cat slept through the storm" and "it was unbothered by the thunder and lightning." These two clauses are joined together by a comma, which creates a comma splice. To fix this sentence, you could replace the comma with a semicolon:

The cat slept through the storm; it was unbothered by the thunder and lightning.

Or you could add a coordinating conjunction:

The cat slept through the storm, and it was unbothered by the thunder and lightning.

You could also use a period to create two separate sentences:

The cat slept through the storm. It was unbothered by the thunder and lightning.

Example comma splice #2

This run-on sentence also has a comma splice:

I love ice cream, it's my favourite dessert.

To fix it, you could use a semicolon:

I love ice cream; it's my favourite dessert.

Or, you could add a conjunction:

I love ice cream, and it's my favourite dessert.

You could also split the sentence into two:

I love ice cream. It's my favourite dessert.

Let's take a closer look at how to correct comma splices.

Our example this time is:

I have a big project due tomorrow, I can't go to the party tonight.

The two independent clauses here are "I have a big project due tomorrow" and "I can't go to the party tonight."

1. Join the clauses with a semicolon

The first fix is to use a semi-colon to more effectively break up the sentence. This works because a semicolon can be used to join two closely related independent clauses:

I have a big project due tomorrow: I can't go to the party tonight.

2. Use a comma and a coordinating conjunction

If you're less confident using semi-colons, another option is to use a comma and a coordinating conjunction like (and, but, or, for, nor, so). The conjunction you use will depend on the logic of the sentence.

I have a big project due tomorrow, so I can't go to the party tonight.

3. Use a subordinating conjunction

If you want to keep the two clauses together, but don't want to use a comma, another option is to use a subordinating conjunction like (after, although, as, because, before, if, since). Again, the conjunction you use will depend on the logic of the sentence.

Because I have a big project due tomorrow, I can't go to the party tonight.

4. Separate the clauses into two sentences

If you don't want to use any of the other options, you can always just separate the two clauses into their own sentence.

I have a big project due tomorrow. I can't go to the party tonight.

Looking to edit your work and remove comma splices (and other errors)? Check out our guide to the five types of editing.

Here are some additional examples of comma splices and how to fix them:

"I love to write, I've been doing it since I was a kid."

"She didn't want to go out, she wanted to stay home and watch TV."

"He's not very good at basketball, he's better at football."

As you can see, each of these sentences has two independent clauses that could stand on their own as separate sentences. Let's use what we've learned so far to fix these sentences:

"I love to write, and I've been doing it since I was a kid."

"She didn't want to go out because she wanted to stay home and watch TV."

"He's not very good at basketball, but he's better at football."

Comma splices are generally frowned upon in formal writing and academic writing, but they can be used effectively in some cases. When comma splices are used, it's important to make sure that the clauses are properly joined and that there is no confusion about the meaning of the sentence.

In general, it's best to avoid using comma splices unless you are confident that you can use them correctly.

As with all grammar, there is a lot of technical terminology — jargon, you might call it — around comma splices. Here are some potted definitions to get you started.

What is an independent clause?

An independent clause can stand on its own as a sentence. It contains a subject and a verb, and it is often defined as containing a "complete thought." In order to be an independent clause, it cannot contain a subordinating conjunction (like "because" or "although").

Here are some examples of independent clauses:

"I love writing."

"She wants to stay home."

"He's not very good at basketball."

What is a conjunction?

A conjunction is a word that joins two clauses together to form a compound sentence. They are usually used to connect two independent clauses, but can also be used to connect a dependent clause and an independent clause. There are three types of conjunctions: coordinate, subordinate, and correlative.

What is a coordinate conjunction?

A coordinate conjunction is a conjunction that joins two independent clauses together. The most common ones are and, but, or, and so. They are used to connect two clauses that have the same weight or importance. For example, imagine you are at a party and someone asks you what your name is.

You might say, "My name is Sarah, and I am from Canada." Both clauses are independent and have the same weight.

If you are having trouble remembering coordinating conjunctions, you can use the acronym FANBOYS: for, and, nor, but, or, yet, so.

What is a subordinate conjunction?

A subordinate conjunction is a conjunction that joins a dependent clause and an independent clause. The most common ones are when, because, if, and unless. They are used to connect two clauses that have different weight or importance. For example, imagine you are at a party and someone asks you what your name is.

You might say, "My name is Sarah, when I am from Canada." The dependent clause (when I am from Canada) is connected to the independent clause (My name is Sarah) by the subordinating conjunction when.

What is a correlative conjunction?

A correlative conjunction is a conjunction that joins two clauses together. The most common ones are either...or, not...but, and neither...nor. They are used to connect two clauses that have the same weight or importance.

For example, imagine you are at a party and someone asks you what your name is. You might say (oddly but grammatically), "Either my name is Sarah, or I am from Canada."

What is a conjunctive adverb?

A conjunctive adverb is a word that joins two clauses together and functions as an adverb. The most common ones are however, nevertheless, furthermore, and moreover. They are used to connect two clauses that have different weight or importance.

For example, imagine you are at a party and someone asks you what your name is. You might say — again, oddly —"My name is Sarah, however I am from Canada." The dependent clause (however I am from Canada) is connected to the independent clause (My name is Sarah) by the conjunctive adverb however.