Editors can do some amazing things. They can make your story shine and find the most impossible-to-find errors. But editors are not miracle workers. They can’t possibly catch every single error, especially in just one read through and especially if the manuscript hasn’t gone through more than one stage of editing.
Most writers don’t understand that a manuscript should go through at least 3 editing steps:
1. Line or content edits
2. Copy editing
It’s essential for writers to know what they can and can’t accomplish on their own. Some authors can perform one or two of these steps themselves, but having a professional editor, if only to perform copy editing, is important to have another set of eyes look over your story. If hiring a professional is the best way to complete all the edits, a different editor should perform each of these steps in order to have a fresh look at your manuscript. Most important: you can’t expect to skip steps 1 & 2 and have a proofreader catch all the errors. It’s impossible.
Another issue is that most of the grammar rules are ambiguous and decided based on perception. What one editor perceives to be an error, another one does not. Also, fiction writing is different from formal writing. Rules are more relaxed in a fiction story because creative writing is based on author and character voice/style. You can get away with having some incomplete sentences in a work of fiction to add impact to the story world, but not in a business letter or term paper. Picking a fiction editor for your book is important. Otherwise, an editor trained only in formal writing will suck the life right out of your story.
From my personal experience working with editors, great ones and not so great, I can say that they don’t catch every mistake. Even the best ones can’t catch everything. And I don’t blame them for that. Ultimately, it is up to the author to make sure his or her manuscript is error free.
Kelley Heckart, Historical fantasy romance author