An edit focused on the mechanical and stylistic errors in the text. A copy edit is vital because it rids your book of the mechanical and stylistic errors that distract your audience from appreciating your writing and your overall story.
This is the stage where you are looking for an expert grammarian. A copy edit entails going word by word to eliminate the existing errors within the text. Now, your manuscript might need extensive sentence restructuring, or it could have relatively simple grammar issues. I can help you determine the extent of work needed on your manuscript after examining a sample.
Issues thoroughly addressed by a copy edit:
grammar
syntax/word choice
spelling
language style
accuracy of facts and figures
internal consistency (e.g., if a character has curly blonde hair on page 3, she shouldn’t have curly red hair on page 5)
general typos
adherence to the appropriate style guide (to prepare for publication)