Overview

A Run-On Sentence (usually identified on a graded paper with the mark R-O or R/O) is a common type of sentence error in student papers.   A run-on sentence is a type of what grammarians call a “fused” sentence.  To fuse two things together is to join them, as if by melting.  This is what happens in a run-on sentence: two sentences, that would be able to stand on their own as complete thoughts, are “melted” together in some way, resulting in a statement that is often confusing and ungrammatical. 

 

 

Run-on sentences have more than one independent clause—a section of a sentence that can stand on its own as a complete thought, with its own subject and verb. 

 

Some examples of run-on sentences are below.  The red words here are subjects; the blue are verbs.  Note how these sentences each have two actors and two actions “mashed together” into one sentence:

 

Mountain lions are not dangerous animals they are beautiful and passive creatures.

 

Emily was my friend she always stuck by me.

 

I was walking home alone I was scared and nervous.

 

My English teacher told me not to take 20 credits I'm regretting not having listened to her.

 

 

In the examples below, the run-on sentences are broken up into their respective independent clauses. 

 

 

Independent clause 1 (contains subject and verb)	Independent clause 2 (contains subject and verb)
[Mountain lions are not dangerous animals]	[they are beautiful and passive creatures.]

 

Independent clause 1 (contains subject and verb)	Independent clause 2 (contains subject and verb)
[Emily was my friend]	[she always stuck by me.]

 

Independent clause 1 (contains subject and verb)	Independent clause 2 (contains subject and verb)
[I was walking home alone]	[I was scared and nervous.]

 

Independent clause 1 (contains subject and verb)	Independent clause 2 (contains subject and verb)
[My English teacher told me not to take 20 credits]	[I'm regretting not having listened to her.]

 

Identifying Run-Ons

 

Exercise: Identifying Run-On Sentences

 

Identify which sentences below are run-ons.  You may find it helpful to look first for the ACTORS and ACTIONS in each sentence; if there are more than one set of each present, the sentence might be a Run-On. 

1. Baked ziti is a wonderful, delicious dish I like to eat it all the time. Run-on?  Y  /  N
2. My cousin Miranda is a top-earning model for Vogue Run-on?  Y  /  N
3. I was dreaming last night I had a new Ferrari but it was stolen. Run-on?  Y  /  N
4. In a couple of years, I will earn more money than my wife. Run-on?  Y  /  N
5. My three year old dropped my iPhone into the toilet and ruined it. Run-on? Y  /  N
6. My three year old dropped my iPhone into the toilet she ruined it. Run-on?  Y  /  N
7. Drinking too much coffee can lead to adverse stomach conditions, such as ulcers. Run-on? Y  /  N
8. I really enjoy country music my brother enjoys hip-hop. Run-on?  Y  /  N
9. Being a parent is a great challenge sometimes I don’t know what to do. Run-on?  Y  /  N
10. Last week I had a horrible cough and I had to stay home from work. Run-on?  Y  /  N

 

 

Fixing Run-Ons

 

Run-on sentences are essentially two sentences mashed together into one.  The basic way to fix a run-on, then is to find a way to connect the sentences (the independent clauses) in a way that is grammatically correct.   There are three basic ways to connect two or more independent clauses and fix a run-on sentence. 

 

Here are some sample run-ons that we can focus on fixing below.

 

Paul is a mechanic he specializes in German cars from the late 1980s and 1990s, and is pretty skilled.

 

Jamie went to the emergency room last night a bike messenger ran over her toe.

 

My brother called me last night at three a.m. it seems he flew to Rome on a moment’s notice and needed me to FedEx him a change of clothes.  

 

 

Method 1:  Break up the run-on into two (or more) complete sentences. 

This is an easy way to fix a run-on sentence—here you simply insert a period at the end of the first independent clause and start a new sentence (with a capital letter).   The only risk in this method is that, if done too often in a single piece of writing, makes the writing sound “choppy” and unsophisticated—i.e., lots of short little sentences make the writer sound amateurish or simplistic. 

Here are a couple of examples of the run-ons above, corrected by making them into separate sentences. 

 

Paul is a mechanic.  He specializes in German cars from the late 1980s and 1990s.

 

Jamie went to the emergency room last night. A bike messenger ran over her toe.

 

My brother called me last night at three a.m.  It seems he flew to Rome on a moment’s notice and needed me to FedEx him a change of clothes. 

 

 

Exercise: Fixing Run-On Sentences / Multiple Sentence Method

 

Fix the following run-ons by breaking them up into two smaller sentences:

 

 

1. My cousin Juliet is very talented she was accepted at the Berklee School of Music and is now a famous pianist.
   
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2. In 2003 the United States invaded Iraq it was a very quick invasion and the U.S. forces quickly destroyed the Iraqi army.
   
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3. Jason and Alexandra went out last week they had a great time.
   
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4. My daughter dressed up like an owl for Halloween last year everyone said she was very cute.
   
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5. Last month a stranger backed into my car he damaged the bumper extensively.
   
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6. The printer in my office always infuriates me it jams up every time I try to use it.
   
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7. My cousin Carlton owns a small food distribution business they deal with hundreds of manufacturers all over the country.
   
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8. My writing is developing well in my last paper I had no run-ons.
   
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9. Walking through the park I had a great thought I would run for political office.
   
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10. My mother had the stomach flu last week she could hardly get out of bed.
    
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Method 2:  Use a semicolon (;) to connect the two independent clauses.   

 

The semicolon (;), which is different than the colon (:) is a punctuation mark specifically used to connect independent clauses in a sentence.  Think of the semicolon as a hook that is only used between independent clauses, or as an equal sign in an equation; the stuff on either side of the semicolon must be an independent clause, just like each side of an equation must be balanced. 

 

Here are our sample run-ons again, here corrected using semicolons:

 

Paul is a mechanic; he specializes in German cars from the late 1980s and 1990s.

 

Jamie went to the emergency room last night; a bike messenger ran over her toe.

 

My brother called me last night at three a.m.; it seems he flew to Rome on a moment’s notice and needed me to FedEx him a change of clothes.  

 

 

 

Here are some other examples of the semicolon in action, connecting some more sets of independent clauses:

 

I am an American; I am also a woman.

 

My sister was almost hit by a car walking home last night; the driver spilled coffee on his lap and jumped the curb. 

 

My feet have been bothering me lately; it seems I need some new shoes.

 

The most populous country on earth is China; India is a close second. 

 

Planned Parenthood provides many medical services for at-risk populations of women; it is the only provider to which some women have access.

 

Recycling is one small way to save the planet; last week I recycled almost every container I used.  

 

 

Exercise: Fixing Run-Ons / Semicolon Method

 

Fix the following run-ons by using a semicolon to connect the two independent clauses:

 

 

1. My English teacher recommended that I do some extra reading over the summer it really helped with building some more sophisticated vocabulary.
   
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2. In 2008, my dad supported John McCain for president I supported Barack Obama.
   
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3. Markus, Lily, and Jasmine went to the movies last night Courtney heard about it and was really jealous.
   
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4. My daughter lost her favorite doll last week and promptly started to panic my wife found it behind the couch.
   
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6. Last month a waiter spilled red wine all over my pants they were ruined.
   
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7. The web server went down yesterday it seems that too many people were trying to access the same information at the same time.
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8. It is amazing to hold a little baby in your arms they feel so fragile.
   
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9. I thought the date was going well she was laughing and talking about herself and her family.
   
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10. When I was seventeen I tripped and fell through a sliding-glass door I had to get a lot of stitches and stay in the hospital for almost a week.
    
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11. My mother is a wonderful person she always takes care of me when I am sick and calls me every week.
    
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Method 3:  Use a Conjunction to connect the independent clauses.  

 

Coordinating conjunctions are words that serve to connect and organize clauses. They sometimes act like a semicolon, serving as a “hook” between two independent clauses. This method of fixing run-ons is most effective when you want to show the logical relationship between the two  independent clauses.

 

The Coordinating Conjunctions:  FANBOYS

 

“FANBOYS” here does not refer to male enthusiasts of science fiction or comic books, but rather is an mnemonic device—an acronym—for remembering the seven primary coordinating conjunctions in English. 

 

 

 

Here are our sample run-ons again, here corrected by the use of one of the FANBOYS coordinating conjunctions.  At times, you might need to re-order your clauses to make the sentence work logically with one of the conjunctions. 

 

Paul is a mechanic AND he specializes in German cars from the late 1980s and 1990s.

 

Last night a bike messenger ran over her toe, SO Jamie went to the emergency room.

 

My brother called me last night at three a.m. BUT it seems he flew to Rome on a moment’s notice and needed me to FedEx him a change of clothes.  

 

 

There are other conjunctions as well that you can use to connect clauses together.  These are called subordinating conjunctions, which, as their name implies, changes or establishes a logical relationship between the clauses.  These words are often added to the beginnings of either independent clause, and used with a comma to make a complete sentence.  They usually establish order, intensity, causality, or some other logical relation in the sentence. 

 

 

Here are some common subordinating conjunctions.

 

After	Although	As
As if	As long as	As though
Because	Before	Even if
Even though	If	If only
In order that	Now that	Once
Rather than	Since	So that
Than	That	Through
Till	Unless	Until
When	Whenever	Where
Whereas	Wherever	While

 

 

 

 

Again, here are our sample run-ons, corrected here by adding some subordinating conjunctions.  Notice, though, how the meaning of the sentence can be altered by using one of these words—several examples of each are given.  All are technically or grammatically correct, but they all mean something slightly different.  It is important to choose the right conjunction for your purposes. 

 

Paul is a mechanic, since he specializes in German cars from the late 1980s and 1990s.

 

Paul is a mechanic, even though he specializes in German cars from the late 1980s and 1990s.

 

Paul is a mechanic, as he specializes in German cars from the late 1980s and 1990s.

 

Jamie went to the emergency room last night, after a bike messenger ran over her toe.

 

Jamie went to the emergency room last night, although a bike messenger ran over her toe.

 

My brother called me last night at three a.m., because it seems he flew to Rome on a moment’s notice and needed me to FedEx him a change of clothes.  

 

My brother called me last night at three a.m., now that it seems he flew to Rome on a moment’s notice and needed me to FedEx him a change of clothes.  

 

 

Exercise: Fixing Run-Ons / Subordinating Conjunctions

 

Fix the run-on sentences below by adding coordinating or subordinating conjunctions to them.  Remember that there is more than one correct answer, and that either the first or second independent clause can contain the conjunction.  You also might need to add a comma when you use a conjunction.  

 

 

1. My geometry teacher recommended that I seek out some tutoring help I really improved my success in trigonometry.
   
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2. In 2008, my grandfather passed away he was sick for a long time.
   
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3. Tom, Kay, and Corey were best friends they had their fights.
   
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4. The dog was really sick he was acting alright.
   
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6. The dry-cleaner I was using switched to a cheaper detergent he could make more money.
   
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7. I found out that my laptop is extra tough it still works after I spilled an entire soda into the keyboard.
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8. The night watchman at the museum really cared about his job he never fell asleep once.
   
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9. Our relationship was fine she cheated on me.
   
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10. When I went to the Grand Canyon I was overwhelmed with its beauty I felt serene.
    
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11. My great-aunt is very dear to me she is an internationally known art thief.
    
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