Run-on Sentence

A sentence is complete only if it expresses a complete thought. A run-on sentence is defined as two complete thoughts written or spoken as one sentence without proper punctuation or connecting words, as shown below.

  • RUN-ON SENTENCE:
    Hepzy went to Montana she saw fifty glaciers.
  • TWO COMPLETE SENTENCES:
    Hepzy went to Montana. She saw fifty glaciers.
  • RUN-ON SENTENCE:
    The invalid devised a plan to go to the market he should stay home until he recovers.
  • TWO COMPLETE SENTENCES:
    The invalid devised a plan to go to the market. He should stay home until he recovers.
  • RUN-ON SENTENCE:
    Second wind is the name given to the return of normal breathing this occurs after a temporary loss of breath.
  • TWO COMPLETE SENTENCES:
    Second wind is the name given to the return of normal breathing. This occurs after a temporary loss of breath.
  • RUN-ON SENTENCE:
    There were no presidents or courts under the Articles of Confederation each state had one vote in Congress.
  • TWO COMPLETE SENTENCES:
    There were no presidents or courts under the Articles of Confederation. Each state had one vote in Congress.

Sometimes one puts a comma where there should be a period:

  • Hepzy went to Montana, she saw fifty glaciers. (RUN-ON)
  • The invalid devised a plan to go to the market, he should stay home until he recovers. (RUN-ON)

Omitting the joining words or punctuation creates a run-on:

  • RUN-ON:
    Some people have no pets other people have one or two some people have many.
  • ONE COMPLETE SENTENCE:
    Some people have no pets, and other people have one or two, but some people have many.
  • RUN-ON:
  • The runner's heart will beat faster, the nervous system will adjust to the higher speed.
  • ONE COMPLETE SENTENCE:
    The runners' heart will beat faster, and the nervous system will adjust to the higher speed.
  • RUN-ON:
    Congress could not tax the people, they asked the states for financial support.
  • ONE COMPLETE SENTENCE:
    Congress could not tax the people, so they asked the states for financial support.

Examples

Tell whether each of the following is a complete sentence or a run-on.

  1. Montana has big mountains it has prairies too.
  2. Miners find gold, silver, and precious gems in Montana.
  3. Summers are warm winters are cold.
  4. High in the cedar tree, the meadowlark is singing.
  5. Exercise makes us feel better it is fun too.
  6. The doctor wearing a white coat.
  7. Water is good for our health.
  8. To play after the rain.

Solutions

  1. This expression is two complete thoughts without punctuation. Therefore it is a run-on. (Corrected: Montana has big mountains. It has prairies too.)
  2. Complete sentence.
  3. This is two complete thoughts without connecting words or punctuation, so it is a run-on. (Corrected: Summers are warm, but winters are cold.)
  4. Complete sentence.
  5. This expression is two complete thoughts without punctuation. Therefore it is a run-on. (Corrected: Exercise makes us feel better. It is fun too.)
  6. This expression is missing part of the verb, so it is a sentence fragment. [Corrected: The doctor wearing a white coat smiled. (or) The doctor is wearing a white coat.]
  7. Complete sentence.
  8. This expression uses the to form of the verb, and it lacks a subject. It is not a complete thought. It is a sentence fragment. [Corrected: I want to play after the rain. (or) I will play after the rain.]

Correcting Run-on Sentences

We correct run-on sentences by adding punctuation or connecting words, and by removing unnecessary words.

Examples 2

Correct these run-on sentences:

  1. Hepzy has a red hen she feeds it corn.
  2. James needs to wash and dry the dishes he should also mow the lawn.
  3. Many people supposed that Henry Hudson was Dutch he was really English.
  4. Congress could print or coin money the states could print or coin money as well.

Solutions

1. We see that the run-on sentence above has two subjects and two predicates, or two complete thoughts.

We may add a period and capital letter to make two complete sentences.

  • Hepzy has a red hen. She feeds it corn.

Or we may add a comma and a connecting word to make a complete compound sentence.

  • Hepzy has a red hen, and she feeds it corn. 

2. We add a period and capital letter to make two complete sentences.

  • James needs to wash and dry the dishes. He should also mow the lawn.

3. We add a comma and a connecting word to make this a complete sentence.

  • Many people supposed that Henry Hudson was Dutch, but he was really English.

We can also correct this run-on sentence by adding a period and a capital letter to make two complete sentences.

  • Many people supposed that Henry Hudson was Dutch. He was really English.

4. We add a comma and a connecting word to make this a complete sentence.

  • Congress could print or coin money, but the states could print or coin money as well.

We can also correct this run-on sentence by adding a period and a capital letter to make two complete sentences.

  • Congress could print or coin money. The states could print or coin money as well.