Chapter 11: Run-on Sentences
Learning Objectives
By the end of this chapter, you should be able to:
- Explain the cause of a run-on sentence
- Differentiate between a fused sentence and a comma splice
- Apply three strategies to fix run-on sentences
Key Terms and Concepts
- run-on sentence
- fused sentence
- comma splice
- coordinating conjunctions
- subordinate conjunctions
- transition words
It’s inevitable. In using a variety of sentence types in your writing, you will have errors. One of the most common errors students have are run-on sentences.
The Basics
Just as short, incomplete sentences can be problematic, lengthy sentences can be problematic too.
As writers we want to ensure our sentences are always form a complete idea to avoid confusion for our reader. A “complete sentence” is also known as an independent clause which we learned about in the previous chapter. Here’s an example:
Both sentences are independent clauses. They both express a complete idea.
However, many people make mistakes when they incorrectly combine two or more independent clauses. This is what is known as a run-on sentence.
A run-on sentence can take two main forms. Before we tell you what those are, so if you articulate it on your own. Read the examples below and see if you can identify what is wrong with each.
Example #2: I have to complete my project by tomorrow, it is worth 30% of my grade.
Example #1 is known as a fused sentence. This means that two independent clauses are combined without any punctuation.
Example #2 is known as comma splice. This means that two independent clauses are incorrectly joined by a comma.
Look at two more examples below. Can you tell which one is a fused sentence and which is a comma splice?
Example #1: We looked outside, the kids were hopping on the trampoline.
Example #2: A family of foxes lived under our shed young foxes play all over the yard.
Example #1 is a comma splice. Example #2 is a fused sentence. Let’s do some more practice identifying the two.
Exercise #1: Fused Sentence or Comma Splice?
Read the run-on sentences below. Decide if they are an example of a fused sentence or a comma splice.
Fixes for Run-on Sentences
While run-on sentences are extremely common, they are also easily fixed by using punctuation, coordinating conjunctions, or subordinate conjunctions.
Punctuation
A period and a semicolon are the most common punctuation marks used to fix run-on sentences.
A period will correct the error by creating two separate sentences.
Run-on: There were no seats left, we had to stand in the back.
Complete Sentence: There were no seats left. We had to stand in the back.
Using a semicolon between the two complete sentences will also correct the error. A semicolon allows you to keep two closely related ideas together in one sentence. When you punctuate with a semicolon, make sure that both parts of the sentence are independent clauses.
Many people mistakenly assume a semicolon can be used like a comma, and that is not correct.
Run-on: The accident closed both lanes of traffic we waited an hour for the wreckage to be cleared.
Complete Sentence: The accident closed both lanes of traffic; we waited an hour for the wreckage to be cleared.
Make sure that both ideas are closely related before you use a semicolon. If they are not related, you cannot use a semicolon.
For example, a semicolon can’t be used in the following sentence because both ideas are not related:
Now, you might be saying, “What if they ate fast food because of the accident? Wouldn’t the two sentences be related then?”
In such a case, you may be right. But it falls on the writer to make that distinction clear to the reader. It’s your job to make sure the connection between your ideas is clear! This can be done with transition words.
When you use a semicolon to separate two independent clauses, you may wish to add a transition word to show the connection between the two thoughts.
After the semicolon, add the transition word and follow it with a comma:
Run-on: The project was put on hold we didn’t have time to slow down, so we kept working.
Complete Sentence: The project was put on hold; however, we didn’t have time to slow down, so we kept working.
We can also apply this to our incorrect example above:
Incorrect Semicolon Use: The accident closed both lanes of traffic; we ate fast food for dinner.
Correct Semicolon Use: The accident closed both lanes of traffic; therefore, we ate fast food for dinner.
Coordinating Conjunctions
You can also fix run-on sentences by adding a comma and a coordinating conjunction.
Remember, a coordinating conjunction acts as a link between two clauses.
Use these words appropriately when you want to link the two independent clauses.
Run-on: The new printer was installed, no one knew how to use it.
Complete Sentence: The new printer was installed, but no one knew how to use it.
Subordinate Conjunctions
Adding subordinate conjunctions is another way to link independent clauses. Like the coordinating conjunctions, subordinate conjunctions show a relationship between two independent clauses. There are many different subordinate conjunctions. Check out this link to see a list.
Run-on: We took the elevator, the others still got there before us.
Complete Sentence: Although we took the elevator, the others got there before us.
In the example above, the run-on is a comma splice, which results from joining two complete ideas with a comma. In the correct example, the subordinating conjunction although appears at the start to show the relationship between the sentences. Now, it’s okay to combine both sentences with a comma.
Here’s another example:
Run-on: Cobwebs covered the furniture the room hadn’t been used in years.
Complete sentence: Cobwebs covered the furniture because the room hadn’t been used in years.
In this example, the run-on is a fused sentence. We fixed this issue by inserting the subordinate conjunction because in-between both sentences.
Exercise #2: Fixing Run-on Sentences
A reader can get lost or lose interest in material that is too dense and rambling. This can easily happen when there are too many run-on sentences in a paragraph. Use what you have learned to correct the following passages. When you think you have a solution, compare it to the possible answer. Changes are bolded and colored purple.
If your answers are a little different, that’s okay, as long as you followed the strategies we discussed. If you’re not sure, please ask your instructor.
Anna tried getting a reservation at the restaurant, but when she called they said that there was a waiting list so she put our names down on the list when the day of our reservation arrived we only had to wait thirty minutes because a table opened up unexpectedly which was good because we were able to catch a movie after dinner in the time we’d expected to wait to be seated.
Without a doubt, my favorite artist is Leonardo da Vinci, not because of his paintings but because of his fascinating designs, models, and sketches, including plans for scuba gear, a flying machine, and a life-size mechanical lion that actually walked and moved its head. His paintings are beautiful too, especially when you see the computer enhanced versions researchers use a variety of methods to discover and enhance the paintings’ original colors, the result of which are stunningly vibrant and yet delicate displays of the man’s genius.
Key Takeaways
- A run-on sentence occurs when two or more independent clauses are connected without proper punctuation
- There are two types of run-on sentences: a fused sentence and a comma splice.
- A fused sentence occurs when two independent clauses are combined without punctuation.
- A comma splice occurs when two independent clauses are combined with a comma.
- Both types of run-on sentences can be fixed by adding correct punctuation, a coordinating conjunction, or a subordinate conjunction to the sentence. The one that’s best depends on the information the writer is trying to convey.
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 on to the next required chapter.
Go To Another Topic
Sentence Fragments | Verb Tense | Punctuation | Eliminating Wordiness
References
Possel, H. (n.d.). Transition Words. Smart Words. https://www.smart-words.org/linking-words/transition-words.html
Traffis, C. (2020, December 16). What is a subordinating conjunction? Grammarly. https://www.grammarly.com/blog/subordinating-conjunctions/
Attributions
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
a clause that can stand on it's own because it conveys a complete idea.
a writing error where two or more independent clauses are connected without proper punctuation
when two independent clauses are combined without any punctuation
when two independent clauses are incorrectly joined by a comma
a word that joins two clauses. These include words like and, but, for, yet, nor, or, so
a word that connects a dependent clause to an independent clause. It shows a cause-and-effect relationship or a shift in time and place between the two clauses
words that are used to connect words, phrases, or sentences. Examples include: as a matter of fact, moreover, in other words, and as a result
