Run-on sentences

Run-on sentences

Author: Ryan Howard

    Introduce run-on sentences and comma splices. 


    Explain ways to correct run-on sentences and comma splices. 


This packet should help a learner seeking to understand English writing style and who has made mistakes with run-on sentences. It will explain how to avoid run-on sentences and correct comma splices.

See More
Introduction to Psychology

Analyze this:
Our Intro to Psych Course is only $329.

Sophia college courses cost up to 80% less than traditional courses*. Start a free trial now.


Using Semicolins

It is possible to correct run-on sentences with semicolons (;)For example:

John is the best runner on the track team he practices everyday.  All that needs to be done is add a semicolon between "team" and "he" In this case, the word "he" does not need to be capitalized. 

John is the best runner on the track team; he practices everyday.

  Here is another example

It is 8:00 the movie started half an hour ago.

Adding a semicolon between 8:00 and "the" allows the the two independent clauses to flow as one sentence.

It is 8:00; the movie started half an hour ago.


In these run-on sentences, insert the semicolon where it belongs.  It's easiest to identify the two independent clauses that can be seen as sentences on their own.


I do not want any cake for dessert it is too fattening.

The gas station has no full-service pumps all their pumps are self-serve.

I prefer cats to dogs they are more independent.

The owl stands on a tree it is wide awake.

Oranges are good for a person's gums they are loaded with Vitamin C.


American Dream Project: Run-On Sentences

Comma Splices

It is possible to separate sentences with a comma.  This is referred to as a comma splice.

John went running, we waited for him at the campground.

Telly is leaving for the weekend, she has to take care of her sick uncle.

However, comma splices on their own can be problematic.  In proper English, there should be a conjunction such as "and," "or," "but," or "so" to connect the independent clauses.  Only periods and semicolons are strong enough to stand on their own without a conjunction.

Let's take a look at the following sentence:

The TV does not work, we have to get it repaired.  We can add a  conjunction between the comma and we.

The TV does not work, so we have to get it repaired.  By adding the cconjunction "so," we were able to leave it as one sentence, but make it more stable.

A few more examples:

Kelly and Dale are coming over for dinner, we need to clean up the house.

This sentence in weak.  We need to add a conjunction.  If we add "and," it will read like this: Kelly and Dale are comingover for dinner, and we need to clean up the house.  See how stronger the sentince is now?

It is time to go to bed, you have to be at your meeting by 6:30.  If we add a conjunction "for," then the sentence becomes complete. 

It is time to go to bed, for you have to be at your meeting by 6:30.

Can you correct the following comma splices?


I went to the mall, I did not see Susie.

Sara and Lynzee were not at school today, they must have been sick.

"Animaniacs" is my favorite show, I hardly ever watch it anymore.

My cats are cute, they can be quite problematic at times.

The cow was eating grass, she did not see us in the pasture.



Run-On Sentence Exercises

Here are a few outside activities relating to run-on sentences.


Avoiding Comma Splices

Avoiding Comma Splices 2

Repairing Run-Ons

Quia - Run-On Activity



What you have learned from this lesson:


  • Run-On sentences are when two independent clauses are joined without proper punctuation.    


  • A period must be added to separate two independent clauses.


  • A comma splice separates two independent clauses, but is not strong enough for them to stand alone.


  • A conjunction must be inserted into the comma splice so that the sentence is more stable.

Source: see above sections for sources