As someone who is not a native English speaker, I face with opinions about book editing. I worked with few editors, but nobody is perfect and almighty. Errors are something that is a part of the book. Even famous authors have errors in their books, but readers are not complaining.
If you are indie author, you need to be perfect, your books must be polished because you are not famous.
It is good to warn readers about bad editing if a book is not readable. What is not fair, is when you based your review only on editing errors.
When you wrote: "A book needs a work of editor. " "A book would be benefited with American or English editor", you are making a bad marketing for the author. The author might have small errors that are not noticeable, but for someone who is thinking about to buy the book, this could be a reason to give up.
Besides, the book can be lost in a translation, when you have some phrases in your language, that doesn't sound the same in English version.
When you write a review, what is important?
Focus on the content, characters, sentences.
Focus on the plot, genre, facts in the book.
Focus on the skill of the narrator, can you read the book?
Sometimes, a book can be perfect edited, but boring, lost in many redundant descriptions.
If you can't read the book because of bad editing, you can talk about errors. But if you can read the book, and failures in editing are not influencing the content, you might avoid to say it public.
I worked with a profreader and I was fixing his errors after I paid him. I worked with another profreader who bring me book back without fixing anything. There are differences between American and British English, too.
What I want to say, if someone write about editing, he might want to take a profit from this. It is not once that someone offered me editing services, trying to get easy money.
If you decide to talk about editing in the review, try to sound diplomatic. "The book is good, but with better editing, it would be great. "


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