ECHO: Run-on Sentences and Comma Splices

What They Are

Run-ons (also called fused sentences) and comma splices occur when a writer incorrectly joins two or more complete sentences (also called independent clauses).

Run-on:   John loved Marsha she loved David.
          I looked for a signal from Mack he waved.
          Chicken Little thought the sky was falling no one believed her.

The above sentences are run-ons because they each contain two complete sentences joined without any punctuation. If we follow our first impulse and use a comma (by itself), we have committed the error of a comma splice.

Comma splice:  John loved Marsha, she loved David.
               I looked for a signal from Mack, he waved.
               Chicken Little thought the sky was falling, no one believed her.

How to Correct Them

  1. A comma splice occurs when two complete sentences are joined by a comma alone. To join two complete sentences with a comma correctly, you must use a coordinating conjunction: but, or, yet, for, and, nor, so

    An easy way to remember these seven words is with the phrase: "Brittney Spears has BOYFANS."

  • But
  • Or
  • Yet
  • For
  • And
  • Nor
  • So

So, the above sentences correctly joined by a comma + coordinating conjunction might look like:

     John loved Marsha, but she loved David.
     I looked for a signal from Mack ,and he waved.
     Chicken Little thought the sky was falling, but no one believed her.
  1. Another way to join correctly two complete sentences is to use a semicolon (;) or a semicolon + conjunctive adverb (followed by a comma). Here, the sentences are corrected with a semicolon alone.
         John loved Marsha; she loved David.
         I looked for a signal from Mack; he waved.
         Chicken Little thought the sky was falling; no one believed her.

    Now, they are corrected with the semicolon + conjunctive adverb (followed by a comma):

         John loved Marsha; however, she loved David.
         I looked for a signal from Mack; finally, he waved.
         Chicken Little thought the sky was falling; however, no one believed her.

*** Notice *** the conjunctive adverbs however and finally are followed by a comma. This is absolutely necessary; otherwise, you have created a comma error (to be covered in a later packet), and English teachers everywhere drag out the red pen . . . .

Some possible conjunctive adverbs and the relationships they express

  • showing addition: also, furthermore, moreover, besides
  • showing contrast: however, still, nevertheless, conversely, nonetheless, instead, otherwise
  • showing comparison: similarly, likewise
  • showing result/summary: therefore, thus, consequently, accordingly, hence, then
  • showing time: next, then, meanwhile, finally, subsequently
  • showing emphasis: indeed, certainly
  1. Still another way to avoid the run-on and comma splice error is to make one sentence subordinate, or dependent, upon the other. This is done by placing a subordinating conjunction at the beginning of the sentence that you consider to be least important of the two. Some subordinating conjunctions are as follows:
    	after		so that		which
    	although	than		while
    	as far as	that		who
    	as if		though
    	because		till
    	before		unless
    	even though	until
    	how		    when 
    	if		    whenever
    	now that	where
    	once		wherever
    	since		whether
    

    And the corrected sentences would look like this:

         Although John loved Marsha, she loved David.
         Because I looked for a signal from Mack, he waved.
         Even though Chicken Little thought the sky was falling, no one believed her.

    If the subordinate (dependent) clause comes first, a comma must separate the subordinate clause from the main clause; however, if the subordinate clause follows the main clause, no punctuation is necessary.

         John loved Marsha even though she loved David.
         I looked for a signal from Mack until he waved.
         Chicken Little thought the sky was falling although no one believed her.
  2. And, of course, the final way to correctly punctuate two sentences is to do just that--make them two sentences. This is done with the common, lowly period (.).
         John loved Marsha.  She loved David.
         I looked for a signal from Mack.  He waved.
         Chicken Little thought the sky was falling.  No one believed her.

    *** Remember *** The ways to correctly join two sentences are as follows:

    • comma plus coordinating conjunction (BOYFANS word),
    • semicolon alone,
    • semicolon plus conjunctive adverb (followed by a comma),
    • subordinating conjunction,
    • or make them two sentences with the use of the period.