Run-on Sentences

A "run-on" sentence occurs when the writer has blended two or more complete sentences into one, either by using no punctuation or by using only a comma.

These are both run-on sentences:

• Leonardo DaVinci was a great painter  he was also an inventor.
• Leonardo DaVinci was a great painter, he was also an inventor.

Here is how you can fix them:

• Leonardo DaVinci was a great painter. He was also an inventor.
• Leonardo DaVinci was a great painter; he was also an inventor.
• Leonardo DaVinci was a great painter, and he was also an inventor.

Note: Complete sentences joined only by a comma are sometimes called a "comma splice," which is a type of run-on sentence error. Using a comma by itself is likely to confuse the reader because commas are used in many other situations. (See the section on comma usage.)

 
To fix run-on sentences:

• Place a period between the two complete thoughts.
• Place a semicolon between the two complete thoughts.
• Place a comma and a conjunction between the two complete thoughts.