Fixing Sentence Fragments & Run-On Sentences

Main Learning Goal and Core Concepts: The goal of this lesson is to recognize a sentence fragment and a run-on sentence. Students will learn to correct these sentences and write complete sentences moving forward.


Sentence Fragment

A sentence fragment is a sentence that is missing either its subject or its main verb.



Example: Went to the store yesterday.



Run-On Sentence

A run-on sentence is a sentence when independent clauses are not joined properly.


Example: Participants could leave the study, they needed to indicate their preference

Lesson Brief

How can we correct sentence fragments and run-on sentences?

Sentence Fragments:

  • Example: Went to the store yesterday.
  • Correction: I went to the store yesterday.

Run-On Sentences:

  • Example: People could leave not the room when the meeting finished, they needed to put down their choice first.
  • Correction: People could leave not the room when the meeting finished. They needed to put down their choice first.


  • If your sentence looks really long and you are using the words “and” or a comma to combine your ideas, it is better to make them into more sentences rather than one long sentence. 
    • If there is a comma within the sentence and it does not make sense when you read it, you should make it into more sentences.
  • With fragment sentences, add a subject word to the sentence, such as “I, he she, they” 
    • You mostly use I if you  need to add a subject
    • If there is already a subject in the sentence but the sentence does not make any sense still, try to take out one word at a time to make it a complete sentence

Take a look at blank template of the practice problems here.

If you want another online writing lesson, additional information can be found here and here.

If you would like a blank copy of the worksheet and the corresponding answer key, they can be found below:

Fragments and Run-On Sentences

Fragments and Run-On Sentences Answer Key