A run-on sentence occurs when two or more independent clauses are joined without proper punctuation or conjunctions. This can make the sentence confusing and difficult to read. For example, "I love to read I go to the library often" is a run-on because it combines two complete thoughts without a conjunction or punctuation. To correct a run-on sentence, you can use a period, a semicolon, or a conjunction. For instance, you could rewrite the previous example as "I love to read. I go to the library often," or "I love to read, and I go to the library often." Proper sentence structure helps improve clarity and understanding.