Run-On Sentences | Return to Film Library

Einstein: Hello! Welcome back. My name is Einstein. I’m a genius, and I’m here to teach you all about grammar.

Alien: Thank you, Mr. Einstein. My teacher tells me that my writing has too many run-on sentences, but I don’t know what a run-on sentence is or what I am supposed to do to fix them, and I have no idea when I am writing a run-on sentence or when my sentence is just fine. So I guess what I am asking is can you please, please, please help me?

Einstein: Absolutely. Let’s get started. A run-on sentence is sometimes called a fused sentence. A run-on happens when you take two or more independent clauses and squish them together into one sentence, rather than writing separate sentences or punctuating them properly.

Alien: So is a run-on sentence always very long?

Einstein: No, run-on sentences can be short or long. As long as your sentence has proper punctuation there is no limit to how long it can be, even thousands of words long. Remember, though, shorter sentences are easier to read and easier to punctuate properly.

OK, here is an example of a run-on sentence:

Alien: “I have found a new planet I come in peace.”

Einstein: You can tell that this is a run-on sentence because it has two subject nouns and two verbs. “I have found a new planet” and “I come in peace” can be written as two separate sentences. That is one way to fix this run-on. You can’t fix it by simply adding a comma: “I have found a new planet, I come in peace.” That is an error called a comma splice. Two independent clauses cannot be separated with a comma. You would need to add a coordinating conjunction with the comma. There are seven coordinating conjunctions: for, and, nor, but, or, yet, so. You can remember them with the acronym FANBOYS. Let’s fix this run-on with a comma and a coordinating conjunction. For example: “I have found a new planet, and I come in peace.” You can also fix a run-on with a semicolon: “I have found a new planet; I come in peace.” Do not use a coordinating conjunction with a semicolon. Also, remember that you must use a semicolon not a comma if you connect two independent clauses with a conjunctive adverb like moreover, however, or nevertheless. For example, “I have found a new planet, however I come in peace” is incorrect. This is still a run-on sentence. You can fix it with a semicolon and a comma: “I have found a new planet; however, I come in peace.” But, in the end, you should keep in mind that usually the best way to fix a run-on sentence is to turn each independent clause into separate sentences.

Alien: Thank you for all that info! It will help me when I write to the natives and tell them I’m coming to invade their planet. Oops! I mean coming to visit.

Einstein: You’re welcome. Let me know if you have any more questions about grammar. Thanks for watching. Bye for now!