A sentence is only big enough for the one sentence... When two clauses can be written as two different sentences and you’ve used a comma instead of full stop, there's a 90% chance you've made an error. Whether it’s in dialogue or not is irrelevant. I ate an orange, it was nice. This is no good, my friend – no good at all. There are two complete clauses. They may feel somewhat linked but that doesn't mean it is okay to splice them together with a comma. The fix is so simple too: I ate an orange. It was nice. That’s usually the intended structure, but it’s not the only way you can fix it. Take a look at this fancy range of comma splice fixes I have to offer you today: * Use a semicolon instead . Only do this when there's an implied link between the two sentences. * Why not throw in a coordinating conjunction? These short and simple words can link your independent clauses together, keeping your comma intact (it will still need the comma). Examples are for,...