A fragment is a group of words that does not express a complete thought. It often lacks a subject or a verb.

A complete sentence is a group of words that expresses a complete thought and contains at least a subject and a verb.

A run-on sentence occurs when two or more independent clauses are joined without appropriate punctuation or conjunctions.

You can fix a fragment by adding the missing subject or verb, or by connecting it to a complete sentence.

A run-on sentence can be corrected using a period, semicolon, or a coordinating conjunction with a comma.

Example: 'When we went to the store.' (This is a fragment because it does not express a complete thought.)

A fragment does not express a complete thought, while a complete sentence does.