Although I’m both a proofreader as well as a developmental editor, these are two very different roles.

For example, as a developmental editor, I'm looking at the big picture and asking myself questions such as:

• Is the story engaging and effective? If not, why not? This is the main question I ask when I’m developmentally editing a story. It leads onto other questions as I try to pinpoint what’s not working as the author intended it to and why.

• Does the pacing work? Ideally, it will ebb and flow to suit the mood of the story and what’s happening in the plot itself. Thrillers are usually fast-paced while a literary novel may move at a slower, more reflective pace. A romantic suspense novel will necessarily include both fast and slow scenes. Every story needs to gain momentum as it moves along, but it also needs reflective scenes to give readers (and characters) breathing space.

• Are the characters believable? By this I mean that they should feel like real people, at least to an extent. This is especially true for the main characters. A secondary question might be whether the characters are relatable, which isn’t the same as being likable. Readers usually want to empathise with the character they’re following—this helps them to emotionally invest in the character (which makes it more likely they’ll want to follow the character on their journey).

• Are there any plot holes? While stories—and plots—naturally evolve as the writer drafts and redrafts, this can sometimes result in stray plot strands that get forgotten along the way. This isn’t the same thing as purposely leaving a minor plot strand dangling only to pick it up in the next book in a series.

As a proofreader, I'm looking at the final product and checking for any remaining (or accidentally introduced) errors. When I’m doing this kind of work, I’m asking myself questions such as:

• Are there any typos? In text that’s being converted to an ebook format, this could look like a number masquerading as a letter, or vice versa. It could also look like two characters posing as one (two lower-case “l l”s instead of an “H”, for example). This isn’t unusual with OCR scanning software.

• Is the formatting correct? By this I mean that all chapter headings are in the same style and in their designated places, that page numbers are consecutive and don’t restart halfway through the book, that the spacing and alignment of the text is consistent, and so on.

• Have any obvious grammar or spelling errors snuck past the copyeditor? No editor can guarantee perfection and every editor will miss something. The more work that’s required on a piece of writing, the more likely this is. Also, because proofreading is the final stage before publication, any amendments must be placed within this context. Sometimes the cost of fixing something is higher than the cost of leaving it alone. This requires good judgment on the part of the proofreader and open communication with the author/publisher.

• Is the style consistent? For example, if an author uses single quotes throughout, there shouldn’t suddenly be a set of double quotes used in dialogue (unless, of course, this is set within the single quotes as a “quote within a quote”). Also, if an author uses a specific spelling variant (such as “spelt” for “spelled”) then this should be applied consistently throughout the text.

The purpose of proofreading is to make sure that a book is ready for publication, which does not mean it will be perfect or 100% error free as that's just not possible.

The purpose of developmental editing is to make sure the story is strong and ready for the next level of editing (this is often line editing or copyediting, depending on the needs of the author and the book itself).