There is an old saying, “rules are meant to be broken.” Although as an editor and a writer, I would never encourage someone to deliberately violate the rules of grammar, there are many instances where this practice is acceptable or even preferable.

Let’s take run-on sentences. I’m sure that you were taught that run-on sentences were incorrect, and it was advisable to avoid them. A run-on sentence is usually defined by linking two sentences that can stand alone as complete sentences and joining them with a comma instead of a period or a semicolon. Here is an example of a run-on sentence: “I went to the liquor store, then I came home.” That sentence is really two sentences, and for it not to be a run-on, you want to add a coordinating conjunction such as “and, or, but, so” (e.g., “I went to the liquor store, and then I came home.”). Problem solved.

But maybe not. Joyce Carol Oates, the author of at least forty books and long-time lecturer at Princeton University, often writes an entire page of a book without using a period. She will simply separate her thoughts by commas. Is this wrong? Bad? Grammatically incorrect? Not necessarily. Oates often wants to create a breathy feeling so that the reader moves from line to line without any paragraphs or pages. She is setting a certain ambiance and giving her book a particular feel. It’s deliberate, and she knows what she’s doing.

Joyce Carol Oates can write run-on sentences because she knows the grammar rules inside and out. If you want to break the rules, know what they are first. Then create a style sheet while you are writing so that you can standardize your practice. You don’t want to have some run-on sentences and some appropriately punctuated sentences in your manuscript if they look and feel similar. Don’t rely on memory if you’re going to violate the grammar rules; write down what you plan to write and why, and have a rationale for doing so.

Copyediting involves going line by line in the document to make sure that everything is correct. The copy editor will remove errors in grammar, spelling, punctuation, and typos. The editor will also establish a style. For example, the author may be Australian, and the book may have been written using Australian spelling. The copy editor will then ensure that none of the spelling appears using standard American terms, which would not fit. The copy editor will also stylize punctuation: the editor and the author will decide if the author wants to use serial commas, commas linking coordinating conjunctions (e.g., “The sun was setting, and it was beginning to get cold.”), and commas after introductory clauses (e.g., “After midnight, the concert hall was almost empty.”).