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Grammar Guides - ENG002: Run-On and Sentence Fragments

This guide is to help students with common grammar problems.

What Makes a Sentence, an Independent Clause, and a Dependent Clause

A sentence has a subject and a verb and is an independent thought. It can be long or short.

For example: picture of dog sleeping

  • The dog slept.
  • The lazy dog slept after chasing squirrels.
  • After a busy morning running errands with his owner and chasing squirrels, the lazy dog slept soundly until dinnertime.

What are clauses?

An independent clause can stand alone (independently!) because it has a subject and verb.

  • Ice cream is cold. 
  • My foot hurts.

Dependent clauses must depend on another clause to make a whole thought. None of these are complete thoughts or sentences.

  • When I first started eating artichokes
  • For another five years
  • The large, lazy dog

Sentence Fragments

Sentence Fragments

Sentence fragments are strings of words that do not form complete sentences. This occurs when a necessary piece, such as a subject (noun) or verb, is missing and/or when the sentence is not a complete idea.

  • Example of a missing subject: Uses methods to encourage classroom participation, including using small groups and clear expectations. (Incorrect. Who uses these methods?). 
  • Possible revision: The teacher uses methods to encourage classroom participation, including using small groups and clear expectations.vintage bowler pic

  • Example of an incomplete sentence: Ending a long history of finishing last in every bowling tournament.
  • Possible fix: Lisa started using a heavier bowling ball, thus ending a long history of finishing last in every tournament. 

Run-On Sentences

A run-on sentence is two or more independent clauses incorrectly joined in a single sentence. 


Fused sentences are two independent clauses put together with no punctuation between them.   

  • The sun came up the dog yawned. Not correct.

Two or more independent clauses included in a single sentence separated only by commas is a comma splice. These are NOT correct.

  • The sun came up, dog yawned. Not correct. 

Fix run-on sentences by:dog yawning

1. Punctuating each independent clause with a period.

  • The sun came up. The dog yawned. 

These sentences are correct (but a little choppy). 

2. Another way to fix run-ons is to separate independent clauses with semicolons.

  • The sun came up; the dog yawned.

3. You can also fix a run-on using one or more commas and one of the following coordinating conjunctions: and, but, so, or, nor, for.

  • The sun came up, and the dog yawned. 

4. Another way to fix a run-on is to subordinate one of the independent clauses. By subordinating a clause, you change the wording so that it is a dependent and cannot stand alone.

  • As the sun came up, the dog yawned.

Adding “as” and “when” made the independent clauses into dependent clauses that could be joined to an independent clause. Sometimes, when you subordinate a clause, you may need a comma.


Other common dependent clause makers are: after, although, as, as if, because, before, even if, even though, if, in order to, since, though, unless, until, whatever, when, whenever, whether, and while.

From Purdue Owl