The comma splice and run-on (or fused) sentence are major punctuation errors that can commonly show up in your writing. What do these terms mean? How can you correct or avoid these errors? ► A comma splice occurs when only a comma separates two independent sentences. ► A run-on (or fused) sentence occurs when no punctuation at all separates independent sentences. Let’s start with two simple sentences: Tony is dishonest. He steals hubcaps for a living. Even though these are simple ideas, both of these statements pass the “independent sentence” test: Each one contains a subject and a verb; each one also expresses a complete thought. In writing your ideas down, you usually are concerned with the meaning and detail of your sentences and often don’t pay enough attention to punctuation, especially where one sentence ends and another begins. That’s when you get into trouble with incorrect punctuation, like this: NO: NO: Tony is dishonest, he steals hubcaps for a living. (comma splice) Tony is dishonest he steals hubcaps for a living. (run-on sentence)
As you can see in these two sentences, comma splices and run-on sentences are similar mistakes. In both cases, the punctuation (or lack of it) does not indicate complete, independent sentences. A comma splice or run-on sentence can also occur when you use transition words: NO: The U.S. Postal Service is usually very reliable, however, sometimes a letter is not delivered for weeks, months, or even years.
Again, there are two independent sentences in the example above. Transition words (like however, therefore, nevertheless, consequently, and then) cannot be used to connect the two sentences. Corrected versions of the previous sentences could be: YES: The U.S. Postal Service is usually very reliable; however, sometimes a letter is not delivered for weeks, months, or even years. OR
YES: The U.S. Postal Service is usually very reliable. However, sometimes a letter is not delivered...