whymzycal has done a fabulous job explaining run-on sentences and how to fix them
here, but let’s have a quick review.
Run-on sentences often creep in to fanfiction (and, sadly, I’ve even seen some examples in profic, too, that didn't appear to be intentional). What is a run-on sentence, you ask? They are sentences that contain too many ideas and too little punctuation.
Sometimes as you’re reading along, you come across something that looks something like this:
Castle wondered how Beckett was able to look at the body without flinching, the man’s face had been bashed in.
Beckett gave Castle her patented eye-roll at his joke he knew they were all right now.
Yep, those are run-on sentences. The first is a comma splice, where two independent thoughts that are hooked together using a comma, while the second is a fused run-on, where the two thoughts are just smushed together without conjunctions or punctuation.
There are a variety of ways to fix run-on sentences. One way is to add a comma and a conjunction that makes one clause dependent on the other.
Beckett gave Castle her patented eye-roll at his joke, so he knew they were all right now.
Adding the conjunction so to the sentence corrects the run-on by making one clause subordinate to the other (and makes my eye stop twitching).
Alternatively, the sentence could be punctuated differently or restructured.
Castle wondered how Beckett was able to look at the body without flinching; the man’s face had been bashed in.
Castle wondered how Beckett was able to look at the body without flinching, because the man’s face had been bashed in.
In the first example, we changed out the comma for a semi-colon, but it would also be correct to use a colon or a dash. In the second, we kept the comma, but, more importantly, we added the word because to help join the two thoughts together.
The last way to fix a run-on sentence is simply to make it into two separate sentences.
Beckett gave Castle her patented eye-roll at his joke. He knew they were all right now.
However you decide to fix those run-on sentences, there’s a way to make it work for the tone of your work and your writing style.
Sources:
Run-on sentencesPurdue Online Writing Lab: Run-onsGrammar Girl: Run-on sentences