Chapter 10: Sentence Fragments

Learning Objectives

By the end of this chapter, you should be able to:

  • Explain the cause of sentence fragments
  • Identify three different types of sentence fragments
  • Apply strategies to fix sentence fragments

Key Terms and Concepts

  • sentence fragments
  • preposition
  • prepositional fragment
  • subordinate conjunction
  • subordinate conjunction fragment
  • gerund
  • gerund fragment

It’s inevitable. In using a variety of sentence types in your writing, you will have errors. One of the most common errors that writers make are sentence fragments.

The Basics

In past writing assignments, your professor may have written the word “Fragment” or “frag” or even “not a complete sentence” on your paper. A sentence fragment is a sentence that is missing a subject or a verb. While the sentence may include a description or may express part of an idea, it does not express a complete thought, and that is the issue.

Look at the example below:


Children helping in the kitchen.

The above example is a sentence fragment. It does not express a complete thought. If you read it out loud, it should sound like something is missing. In this case, a verb is missing.

Now, you might say, “Wait a minute, isn’t ‘help’ a verb?” Well, often it is a verb, but in this case it is not. What we have here is known as a gerund phrase. We’ll explain this in more detail in a little bit, but, essentially, what that means is that the entire phrase above serves as the subject for the sentence. That’s right! Multiple words can combine to make a single subject!

Thankfully, you can easily fix this type of fragment by adding the missing subject or verb. In the example, the sentence was missing a verb. Adding often make a mess makes this a complete sentence.

Children helping in the kitchen often make a mess.

It’s that easy! If someone tells you there is a sentence fragment in your writing, first figure out whether you’re missing a subject, verb, or both, and then fill it in.

Exercise #1: What is Missing?

Read each sentence fragment below and decide if a subject or verb is missing. Then, try to come up with a fix on your own. Click on the arrow to check your answer.

Before we dive into different types of sentence fragments and how to fix them, here’s a short video that will provide an overview.

Link to Original Video:

Identifying Sentence Fragments

Let’s get a little more technical now. We know that a sentence fragment occurs when a subject or verb is missing from a sentence. Sentence fragments also occur because of some common error, such as starting a sentence with a preposition, a subordinate conjunction, or a gerund don’t worry, we’ll explain what those are in a minute. If you use the four basic sentence structures when you write, you should be able to avoid these errors and thus avoid writing sentence fragments. Nevertheless, mistakes still happen, so it’s important to know what to look for while you revise.

Preposition Fragments

Prepositions serve a lot of different purposes. These are words such as in, on, at, of, and under (and there are many, many more). Essentially, they are used to show relationships between words.

For example:

The dog is under the table.

under is the preposition as it shows where the dog is in relation to the table. For more background on what a preposition is, check out this link from Grammarly.

When you see a preposition in a sentence, check to see that it is part of a sentence containing a subject and a verb. If it is not connected to a complete sentence, it is a sentence fragment.

Here is an example of a preposition fragment:

After walking two miles.

In the above example, after is the preposition and we are also missing a subject. Who is walking the two miles?

Let’s try this again.

After walking over two miles. John remembered his wallet.

Now we have two sentences. Does that fix the problem? We know who did the walking now. It’s John.

Well, no. It doesn’t. “After walking over two miles” is still a sentence fragment because it is missing the subject. Even if it’s explained in the next sentence, it still doesn’t work grammatically because it’s not a complete idea.

Luckily, the problem is an easy fix. You can combine the sentence fragment with the second sentence.

The easy way is to replace the period with a comma:

After walking over two miles, John remembered his wallet.

You can also rearrange the sentence so the preposition fragment goes at the end of the sentence. Just make sure you drop the comma.

John remembered his wallet after walking over two miles.

Is one version better than the other? Technically, no. As with all writing, the best approach depends on context. If you have an entire paragraph that starts with only prepositional phrases, it’s going to look a little odd. It’s all about balance and using a variety of sentence structures to make your writing stand out.

Subordinate Conjunction Fragments

Do you remember subordinate conjunctions from the chapter on sentence structure? Subordinate conjunctions include words such as sincebecausewithout, or unless. Like prepositions , they serve many different purposes. For more background on how subordinate conjunctions work, check out this link from Grammarly.

Take a look at the incorrect example sentence below. In this case, because is the subordinate conjunction.

Because we lost power. 

“Now hold on!” you might be saying, “you said at the start of this chapter that a sentence fragment is missing either a subject or a verb, and that first sentence has both!”

You’re right. It does. There is a subject (we) and a verb (lost), but since the sentence begins with “because,” it does not feel like a complete idea. Read it out loud. It should sound like something is missing. Its incompleteness suggests that it’s a sentence fragment, and more specifically, a subordinate conjunction fragment! Fortunately, there is an easy fix. Let’s add another sentence just like last time.

Because we lost power. The entire family overslept.

Does something about this type of sentence seem familiar? It should! Structurally, it should remind you of the prepositional fragment we just fix. Many writers will try adding a another sentence to fix their sentence fragments like in the example above and not actually fixing anything! The example above is obviously still wrong, but its similarity to the prepositional fragment example suggests how to fix it.

Because we lost power, the entire family overslept.

The entire family overslept because we lost power.

Be sure not to forget to include that comma between the two sentences if the subordinate conjunction starts the sentence.

Gerund Fragments

Gerunds are a little more complicated. Essentially, when a word ends in -ing, it can be either a noun, an adjective, or a verb. If the -ing word is noun, or, in some cases, an adjective, then it is known as a gerund.

Let’s use the word “singing” as an example.

She is singing at the festival tonight.

In the above example, singing is combined with a helper verb (is) to make is singing. In this case, singing is being used as a verb.

Now look at this example.

Singing is what I was born to do!

Don’t be fooled! Singing looks the exact same, but it’s not being used as a verb anymore. It’s a noun! More specifically, it’s the subject of the sentence. Now it’s agerund!

Let’s look at one other example with the word working:

Verb: I was working on my part of the report until midnight.

Gerund: Working on reports until midnight make me tired the next morning.

In the first sentence, working has a helping verb (was) which means it’s the verb form. In the second sentence, working is being used as the subject of the sentence, which makes it a noun. Therefore, it is a gerund.

If you need a little more help understanding gerunds, check out this link from Grammarly.

So what do these gerunds have to do with sentence fragments? Let’s look an an example of a gerund fragment:

Taking deep breaths. Saul prepared for his presentation.

In that example, taking is the gerund. Does the first sentence make sense on it’s own? Does it sound like a complete idea?

No. It doesn’t.

So how do we fix this? Well, like the other two fragment types we covered, we can combine the fragment with the next sentence by using a comma instead of a period.

Taking deep breaths, Saul prepared for his presentation.

You can also rearrange the order of the sentences. However, when you do that, you may have to add words so it makes sense.

Saul prepared for his presentation by taking deep breathes.
You can also change the gerund back into a verb by changing the structure of the sentences.
Saul prepared for his presentation. He was taking deep breaths.

Notice that we can tell taking is a verb now because it has a helping verb (was).

Sentence Fragment Review

As we’ve seen, sentence fragments can take many different forms. Fortunately, they are easy to fix. It’s all a matter of knowing what to look for and making sure your fixes make sense. Let’s test your understanding now.

Exercise #2: Identify and Fix the Sentence Fragment

Below you will see two sentences. One will be a sentence fragment, the other will be a complete sentence. First, identify which sentence is the fragment and what type it is: a preposition fragment, a subordinate conjunction fragment, or a gerund fragment.

Next, come up with a fix so that both sentences make grammatical sense. The solution will provide two possible solutions, since there are many ways you could fix the sentences. If you’re not sure if your solution works, please check with your instructor.

If you would like to watch another video on sentence fragments, try this one:

Link to Original Video:

Key Takeaways

Now that you are finished with this chapter, you can either click on one of the other sentence-level issues and learn about them, or continue to the next required chapter.

Go To Another Topic

Run-On Sentences | Verb Tense | Punctuation | Eliminating Wordiness


EnglishClub. (n.d.). Preposition list

Grammarly. (2017, April 7). Gerund.

Ross, B. (2021, January 14). Prepositions. Grammarly.

Traffis, C. (2020, December 16). What is a subordinating conjunction? Grammarly.


This chapter is adapted from “Communication at Work” by Jordan Smith (on Open Library). It is licensed under Creative Commons Attribution 4.0 International License.

This chapter is also adapted from “Writing for Success” by University of Minnesota (on University of Minnesota Libraries Publishing). It is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License



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Effective Professional Communication: A Rhetorical Approach Copyright © 2021 by Rebekah Bennetch; Corey Owen; and Zachary Keesey is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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