At times it may seem strange to call in an editor to work on your fiction. Afterall, it’s fiction and the writer has freedom to do whatever want, right?
Well, the answer is yes but only within reason, and only when the writer has good reason to break from convention.
Who chooses the rules? As the writer, you do! But the rules still have to make sense and they need to be consistent throughout your writing.
For this reason, before I start working on a project, I like to have a conversation with the author about their work. What are the rules they’ve created? What are the conventions they are using that they didn’t create themselves? Do you want to follow a specific style guide for grammar and capitalization? (I suggest Chicago Manual of Style for fiction writers in the US.)
However, none of our standard English rules even matter if you haven’t created the rules of your world.
In developmental editing, instead of worrying about the spelling and form of each word in each sentence, the editors job is to zoom out as far as they can. The overall story must be strong and resounding before work can be done at a more minute level.
The Editing Klingdom 