Compound Sentences

And Their Arch Nemesis, the Comma Splice

Have you ever had such a great idea that you just couldn’t stop raving about it? The words come pouring out of your mouth, with your voice barely able to keep up with your brain. The excitement bubbles up, and you couldn’t stop the verbal outpour even if you wanted to. Yeah, that’s a good feeling. That’s kind of how compound sentences work. You’ve got this one sentence that’s so great, and you know what would make it even better? Yes! A second sentence!

Okay, maybe there’s a little more to a compound sentence than just two sentences smashed together. Let’s explore these sentence structures a little more thoroughly. Here’s a fancy-shmancy definition of a compound sentence structure:

A compound sentence is a combination of two independent clauses, both of which focus on the same idea or topic. Each independent clause contains its own subject and predicate, and they’re usually joined by a coordinating conjunction. There are no dependent clauses within this sentence structure.

Whoa. That’s a lot of terminology. Don’t be intimidated, though! We can work through this together.


The Building Blocks of Compound Sentences

First, it’s important to know what an independent clause is. Basically, she’s a strong, independent clause who don’t need no man… Oh, wait. That’s not right. Let’s try that again.

An independent clause is a group of words that can stand alone as its own complete sentence. But, it’s not your average group of words. There’s a specific type of words that need to show up in every independent clause. That’s where the subject and predicate come in. A subject is the noun of the sentence (who, or what, the sentence is all about), and the predicate is what the subject does. At its most basic, a predicate is a verb.

What do these independent clauses look like, though? Here are some examples to help you better understand. Pay close attention to the subject and predicate of each:

  • Abby loves her new puppy.
  • The high school football team is undefeated.
  • Write from the Heart Classes has the best writing coaches ever. (*wink wink*)
  • Independent clauses stand alone as complete sentences.

In contrast, a dependent clause is a group of words containing a subject and a predicate, but it doesn’t make a complete sentence. It’s completely dependent on an independent clause to become a complete and grammatically-correct sentence. That’s a lesson for another day, though. Just know that if it’s not an independent clause, it doesn’t belong in a compound sentence.


Strategies for Structuring Compound Sentences

Using a Semi-Colon

To turn these independent clauses into a compound sentence, we can use something as simple as a semi-colon. It’s like sentence glue. By placing it between each independent clause, we’ll create a grammatically correct compound sentence. Check out some examples:

  • I perused the pages of my Bible; inspiration soon crept into my consciousness.
  • Soda has a lot of sugar; you should avoid consuming too much.
  • There’s nothing like a fresh notebook and new pen; having them makes me want to write something.
  • I’m getting so old; why can’t time slow down?

Notice that these sentences all have another element from our definition: each independent clause within the compound sentence focuses on the same topic or idea. You wouldn’t want a compound sentence where the clauses weren’t related; that’d be confusing. Keep that in mind as you write.

Using a Coordinating Conjunction and a Comma

Going back to our definition of a compound sentence, there’s also a little something called a coordinating conjunction. That’s a big ol’ name for a group of super small words. Seriously. Each coordinating conjunction is three letters long or less. And, there are only seven of them.

To remember all of our coordinating conjunctions, we can use the acronym, FANBOYS. They’re like fangirls, but they tend to keep their composure around famous singers and bands a little better. Maybe not…

They’re super handy for our compound sentences, though! Here’s a breakdown of our coordinating conjunctions:

F – For
A – And
N – Nor
B – But
O – Or
Y – Yet
S – So

Yep. That’s all of ’em.

But, how do these help us create compound sentences? Think of them like the zipper on a backpack, keeping everything from falling out behind you. And what is a zipper without that little tabby-thing to grab and pull? You’d never get that zipper opened or closed without it, just like you can’t have a compound sentence without a comma. When you write out your compound sentence, that comma needs to follow directly after the first independent clause. Then comes the coordinating conjunction, followed by the second independent clause. It’s like a sentence structure conga line (da-da, da-da, da-DA!)

Here are some examples of compound sentences using those coordinating conjunctions:

  • I filled the blender with fruit, and I watched as the blade pulverized it into a smoothie.
  • I woke up late, but I still managed to catch my bus to school.
  • You can read a book, or you can work on your science homework.

Compound sentences… they’re a thing of beauty, aren’t they?


Comma Splices: One of Grammar’s Greatest Enemies

We love commas. They’re so handy! We can use them to separate clauses in complex sentence, to insert an appositive or an interjection, or even to indicate a natural pause where we can take a breath while we read. They’re like little superheroes of the sentence structure world. But, sometimes heroes fall. And they become not-so-hero-ish.

Imagine you’re writing a compound sentence, and you decide to split up those independent clauses using a comma. But, if you forget to add in a coordinating conjunction, you get something like this:

Commas are a great tool, you shouldn’t use them to separate two independent clauses.

In that sentence, we’ve got two independent clauses:

  1. Commas are a great tool.
  2. You shouldn’t use them to separate two independent clauses.

But, we don’t have a coordinating conjunction. We’re missing a major component of our sentence structure conga line!

To make that sentence correct, we’ve got to add in one of our FANBOYS:

Commas are a great tool, but you shouldn’t use them to separate two independent clauses.

Those coordinating conjunctions help Super Comma complete its task of separating those two independent clauses correctly; make sure you don’t leave it out.


Want to Practice Your Skills?

Here are a few sentences that contain commas, but some of them need a coordinating conjunction! Find the sentences with two independent clauses, and add in a coordinating conjunction to make them correct.


  1. Chocolate is my favorite, I’ll eat vanilla if that’s the only option.
  2. Before we went to the store, we ate a huge breakfast.
  3. I enjoy writing fictional stories, I’m good at academic essays.
  4. Watching too much TV will rot your brain, you should read a book instead.
  5. Although the hero was good at his job, he longed for a normal family.


Answers: #1, 3, and 4 all contained comma splices.





 Author: Stephanie Constantino

Mrs. Constantino - Compound SentencesMrs. C is a teacher, writer, and stay-at-home mommy extraordinaire. She loves pushing students to the boundaries of their writing potential through using a fun and encouraging teaching style. If you’d like the opportunity to work with Mrs. Constantino, or any of the amazing Write from the Heart coaches, send an email to