Fragments and Run-on Sentences

Fragments and Run-on Sentences Video

Do you ever have an idea you want to share but struggle to find the right words?

Sometimes, we only have a fragment of an idea, and sometimes our brains think in quick succession, running on and on from one idea to another. This can sometimes result in grammatical errors in our writing that hinder our ability to communicate effectively.

So how can you keep this from happening in your writing?

Let’s find out!

Today, we’ll be taking a look at fragments and run-on sentences. Although they are on opposite ends of the spectrum, both of these grammatical errors can be problematic when trying to communicate an idea. In this review we’ll cover the following questions:

  • What are fragments and run-on sentences?
  • How do I identify them?
  • How can I revise them to improve my writing?

But first, we need to have a clear idea of what our end goal is: let’s start with creating sentences.

What is a Sentence?

A sentence is a series of words and punctuation that conveys a complete idea. A sentence must, at minimum, contain a subject and a predicate while also communicating a complete idea. The subject is the main focus, who or what, of the sentence, and the predicate uses a verb to describe an action related to the subject.

“The rabbit eats hamburgers” is an example of a basic sentence. Here we have the subject, the rabbit, followed by the verb eats, which describes what the rabbit is doing. Together, these communicate a complete idea.

Sentences can become much more complex but will still retain a subject and predicate. “The rabbit always eats hamburgers on Tuesday” still conveys information about the subject, the rabbit, and uses the verb eats but provides more context.

Now that we understand how sentences are built, we can look at two different parts of speech that are related to sentences: fragments and run-on sentences.

What is a Fragment?

A fragment is a set of words that do not form a complete sentence on their own. Since we know that sentences must include a subject and predicate to be complete, we can infer fragments are often missing one or both of these elements. There are, however, cases where a fragment has both a subject and predicate but does not communicate a complete idea on its own.

Let’s take a look at some examples of fragments.

Identifying Fragments

An easy way to identify a fragment is to assess whether the reader would be left with any questions about the meaning of the message being conveyed.

Going back to our previous example, if we take away the verb eats, we would be left with the following fragment: The rabbit always hamburgers on Tuesday.

As you can see, this leaves out some vital information. What does the rabbit do with the hamburgers on Tuesday? Does it eat them? Make them? Steal them? Without a clearly defined verb for our predicate, we are left with this important question.

Can you identify which of the following examples are fragments?

  • The chef made too many waffles.
  • Swims as quickly as it could
  • When we go to the beach

The first example is not a fragment. We know who the subject is (the chef) and what they did (made waffles).

The second example is a fragment. We know that the verb is swims, but there is no clear subject indicating who or what swims.

Our third example is also a fragment. Although it contains a subject (we) and a predicate (go to the beach), the word when is conditional, so we are left with an incomplete thought. We are left with the question, “What happens when we go to the beach?”

Once we identify a fragment, we can then work on turning it into a complete sentence.

Revising Fragments

In order to revise a fragment, we simply need to insert the missing subject or predicate.

In the example “Swims as quickly as it could,” the resulting question is “who swims,” indicating that we are missing a subject. We could make the sentence about a penguin by saying, “The penguin swims as quickly as it could.”

Let’s take a look at one more example of a fragment. Here we have a dependent clause: After the penguin swims

Because of the addition of the word after, we are led to ask, “What happens after the penguin swims?” Since we have our subject (the penguin) and predicate (swims), this tells us that we need add an independent clause to complete the sentence. Let’s add the independent clause “It eats hamburgers with the rabbit.”

Now we have a subject, a predicate, and an answer to our previous question of what happens after the penguin swims.

While fragments are incomplete and leave the audience with questions, we can also sometimes provide too many ideas in one, resulting in a run-on sentence.

What is a Run-On Sentence?

A run-on sentence is the result of two or more clauses being combined together incorrectly. With too much information being shared at once, run-on sentences are often confusing and don’t have a clear meaning. This is typically the result of failing to use conjunctions or proper punctuation.

Identifying Run-On Sentences

Identifying run-on sentences can work similarly to identifying fragments, but instead of missing information, a run-on sentence will provide too many options for a given question.

Let’s try combining two clauses together about a rabbit and a dog that eat hamburgers:

  • The rabbit always eats hamburgers on Tuesday the dog eats too.
  • The rabbit always the dog eat hamburgers too on Tuesday.
  • The rabbit always eats the dog eats hamburgers on Tuesday too.

Uh-oh. Now if we’re asked “who,” we’re not sure if the sentence is about the rabbit or the dog. It is also difficult to tell what they are doing. Who is eating what and when? Is the dog eating hamburgers? Is the rabbit eating the dog? What exactly is happening on Tuesday?

Luckily, we can clear up this confusion using punctuation and conjunctions.

Revising Run-On Sentences

Our goal is to communicate that both animals eat hamburgers.

One option is to completely separate the clauses into two distinct sentences using punctuation, which are marks used to clarify meaning by dividing sentences and sentence elements.

The result may look something like this: “The rabbit always eats hamburgers on Tuesday. The dog eats hamburgers too.”

Here, we have two complete sentences separated by a period. Each sentence is an independent clause that can stand on its own, and there is no confusion about elements from each sentence and how they influence each other.

Alternatively, we can use a conjunction to revise our run-on sentence. A conjunction is a word used to connect clauses together.

One of the most common conjunctions is the word and. When applied to the previous example, we can create the following sentence: “The rabbit and the dog always eat hamburgers on Tuesday.”

Our conjunction and helps us connect the two subjects and tie them to the same predicate for clarity.

We could also put the clauses back-to-back with our conjunction in the middle: “The rabbit always eats hamburgers on Tuesday, and the dog eats hamburgers too.”

In this example. we also have a clear connection between each subject and predicate but with a slightly different meaning based on the placement of the conjunction.

In today’s review, we covered two common grammatical errors: fragments and run-on sentences.

Remember that a fragment is a set of words that do not form a complete sentence on their own. Fragments will leave their audience with a question. They can be corrected by adding the missing subject or predicate.

On the other hand, a run-on sentence is the result of two or more clauses being combined incorrectly. They have too much information and can be revised by adding a conjunction and/or proper punctuation to clearly define each clause as a separate or related idea.

That’s all for this review. Thanks for watching, and happy studying!

Frequently Asked Questions


What is a sentence fragment?


A sentence fragment is an incomplete thought. In other words, it is a phrase or clause that is missing a main subject or verb. Here are a few sentence fragment examples:

“Climbed up the mountain”
“Before the storm rolls in”
“The large black bear”


How do you fix a fragmented sentence?


There are a few things you can do to fix a fragmented sentence. You can try attaching the fragmented sentence to another complete sentence in the text; determine what is missing from the sentence, then add whatever the sentence needs, such as a subject, verb, or direct object; or completely rewrite the sentence to make it a complete thought.


What is a run-on sentence?


A run-on sentence usually consists of two or more independent clauses that are not joined correctly. Here are a few examples:

“He ran the experiment for several hours and he didn’t see any results and so he went back to the drawing board and he came up with another experiment.”

“The leaves began to fall from the trees, it was starting to look more and more like autumn.”


How do you fix a run-on sentence?


Run-on sentences are often fixed by adding punctuation and conjunctions to break up the sentences. Take the following run-on sentence for example:

Run-on: “Hila likes green apples but she prefers red apples and Ollie likes green apples too.”

Fixed: “Hila likes green apples, but she prefers red apples. Ollie also likes green apples.”


How do you avoid run-on sentences?


Avoid run-on sentences by utilizing commas, semicolons, conjunctions, and periods to break up sentences.



by Mometrix Test Preparation | This Page Last Updated: April 1, 2024