Pasadena City College, Home of the PCC Lancers

WAC/Health Sciences

Frequently Made Mistakes in Grammar and Mechanics

Run-on sentences

Run-on sentences are sentences that join two or more complete sentences (i.e., independent clauses) without punctuation.  In other words, run-ons have a sequence of ideas (or clauses) that are not separated by periods, commas, or conjunction words like and or but.  

  • In this example there are too many ideas (i.e., clauses) that run-into each other. 
    • WRONG:  The students in auto shop took apart the engine they studied for the final test.
    • The run-on can be fixed by writing two complete sentences.
      • CORRECT:  The students in auto shop took apart the engine.  They studied for the final test.
    • The run-on can also be fixed by adding a comma and a conjuncting word.
      • CORRECT:  The students in auto shop took apart the engine, and they studied for the final test.