Proofreading certifies a copy edit and rectifies typos, spacing errors, and layout issues. Copy editing improves the readability and effectiveness of a text, and these are based on different elements, such as grammar, syntax, usage, punctuation, etc. Consequently, the level of copy editing a text requires depends on how these elements have been employed by the writer.
Regular copy editing ensures that all errors in grammar, spelling, punctuation, and usage are rectified and that the consistency of all content (e.g., footnotes, tables, figures, and references) is verified. If a text presents convoluted and inconsistent prose, then heavy copy editing must be applied to clarify incorrect syntax, remove redundancies, and rewrite incoherent prose.
Regular copy editing requires less time to perform than heavy copy editing; therefore, the fees for these two different services vary. I require a sample of the text to determine the level of copy editing it needs. I analyze the grammar, usage, spelling, punctuation, syntax, and consistency of the prose while considering the motivation, objective, process, and audience of the writer. Based on this assessment, I establish the quote for the entire text.