Run-on sentences, also known as fused sentences, occur when two complete sentences are squashed together without using a coordinating conjunction or proper punctuation, such as a period or a semicolon. Run-on sentences can be short or long. A long sentence isn’t necessarily a run-on sentence.
To avoid run-on sentences, see if there is more than one idea communicated by two or more independent clauses. In our examples, there are two complete sentences:
Both sentences are complete ideas by themselves; therefore, use a semicolon or a period to indicate that they are separate independent clauses.