Run-on Sentences


Run-on sentences are a common grammar error. 

People seem to want to write just as they talk – and that is probably what causes this common grammar error.


We let our mouths “run on” about almost anything, and our sentences also do the same.


If I am talking, I might feel comfortable joining my sentences (my complete thoughts) with the conjunction “and,” and then I just keep going on and on, and adding more sentences, and more sentences, and my sentences end up getting longer and longer and longer and, finally, what I end up with is a true run-on sentence because my words just run on and on and on and I add more and more and I never think about stopping to take a breath, or if I do stop to take a breath, I add another “and” and continue on.


Yes, the paragraph above is one sentence – and it is a “run-on sentence.”

It may be quite all right to speak that way, though professional speakers and formal speakers would take the time to think in short sentences.  Always speak and write for your audience.  


Formal writing and formal speaking are certainly much different from the regular loose speech that one might use around local friends.  However, it is important to remember that your speech is going to define you.  Unfortunately, that is true.  


Perception is reality.  

If you speak well, and use a good vocabulary, you will be considered intelligent and educated. 

If you speak the slang and street language and use the common words of the street with no heed of good grammar and pronunciation, you will be placed into another category altogether.  

If you are reading about grammar, I would hope that your goal is to improve yourself in this regard.

Run-on sentences

Quick summary.  This type of long and wordy sentence is simply thought after thought after thought placed alongside other thoughts without the appropriate punctuation separating them.  It may be okay for speech; it is not acceptable in formal writing.

To write accurately, therefore, you must understand what is a sentence.


SPECIAL LINK - Click this link to read more about sentences structure.

SPECIAL LINK - Click this link to read about sentence fragments.


Here is an example

  • Each sentence must end with a period. 
  • Each sentence must be a complete thought. 
  • Each sentence can be short and clear.

The three sentences above are short and complete.  Each has a subject and verb.  Each ends with a period.
If I join the sentences, I must join them in a particular format.


I can join them with semi-colons:

Each sentence must end with a period;  each sentence must be a complete thought; each sentence can be short and clear.

  • Above, the changes are that the semi-colons take the place of the periods. 
  • The capitals at the start of the second and third sentences have been removed because they no long begin a new sentence.  
  • Now the three sentences have been combined into one long sentence, but the new sentence is properly punctuated.


Normally, you would combine sentences only if the meaning is similar or if the sentences are somehow related logically.




Another solution

Another way to join the sentences - Add a conjunction “and” or “but.” 

If you do that, you must add a comma at the end, and then the conjunction.  Consider:


Each sentence must end with a period, and each sentence must be a complete thought, and each sentence can be short and clear.

  • In the above, I added a comma and then a conjunction between the sentences. 

Normally, this works well if there are two sentences being joined.  With three, I hope you can see how the sentence sounds a bit awkward. 

If you really want to join the sentences, here is another consideration – using only one of the conjunctions:

Each sentence must end with a period;  each sentence must be a complete thought, and each sentence can be short and clear.

  • In the above, the semi-colon remains to join the first two. 
  • The second and third have been joined with the conjunction. 
  • Reading the above does sound much better.


So, in summary


You can join sentences with punctuation or with conjunctions.  

SPECIAL LINK - Read more about conjunctions here.

SPECIAL LINK - Read more about the semi-colon here.


Another way to create a run-on sentence


Another way to create a run-on sentence  – in error –  is to use the comma instead of the semi-colon – or instead of the period – at the end of the sentence.

  • Placing a comma instead of a period at the end of a sentence will create the error known as the run-on sentence. 
  • Because it uses a comma to join together two sentences, this error is also called a comma splice.


Each sentence must end with a period, each sentence must be a complete thought, each sentence can be short and clear.

  • Above, the period at the end of each sentence has been replaced with a comma. 
  • Again, this is an error. 
  • We have above a run-on sentence, but it’s also known as a comma splice.


SPECIAL LINK - Read more about the comma splice.

SPECIAL LINK - Read more about comma rules.


Periods - not commas - belong at the ends of your sentences.

Strive for success!


LINK - Return from run-on sentences to Sentence Structure.


LINK - Click this link to find an excellent course in business writing.