I don't know what I should do when reviewing a completed work of fiction. Would you the writers, like it if we readers review every chapter or review the completed work in the ending? It seems to me that a review of the entitled work, would be the why to go. Though, I'm unsure what would be best?

Also what do the writers want in a review. I have read a few writers get upset over a review. I known that some people are just mean to the bone. And because this is the Internet some people are rude and act entitled. For me, I don't want to make the artist upset. So what and how do we review? Do we write about thinks that we think are wrong or right? I know it can't be wrong, being it's the artist storyline. But sometime I see where they may have gone off script a little or really seemed to misunderstand a personality. Then what about grammar, spelling and just using the wrong word? I known that no one is a paid writer here and this is a hobby. The writers are giving use their time and personal written words. I personally feel that a reader should review with that in mind. If the reader is upset with the writers grammar don't leave a mean review. If you can't say something nice or helpful don't read it the story. But if it would help the writers, we the readers would love to help. What would be the best way to go about it?

Alright, last one. Do the writers want use readers to review at more than one site? I find sometime I start out on FanFiction reading, and then move to Dokuga to finish, because of the lemons or the story stopped and finish on another website. So part of my review maybe on FanFiction then the other part is on Dokuga. What's the right thing to do here?

As you can see I'm no writer, so if you have any questions for me feel free to ask.

The things you're asking about here wade deep into the waters of individual preferences so it's impossible to definitely answer them. Every author has different experiences and opinions. Some might welcome constructive criticism, some might not.

Whether a review might come across as annoying to a writer also depends on a lot of different contextual factors not related to the actual review itself. The writer might be having a bad day. The writer might have received several comments in a similar vein so one comment just happens to be the straw breaking the camel's back.

The point is, you shouldn't overthink it. There is no right or wrong way to review a story. Every reader has their own way of reviewing and writers will come across a lot of different types. Some people like to review every chapter even on a completed fic, some people only leave one review on the last chapter, some people might comment on a few chapters along the way where something notable / something they want to comment on happens.

I think generally speaking pointing out grammar errors, typos and wrong word usage would be ok to most writers as long as you do it politely and that is not the only thing your comment consists of. If you want to help you should also be specific about the mistake you saw. Just telling the author they have grammar errors isn't very helpful because then they won't know what exactly they need to fix.

Finally, here are some links you might find useful:

Feedback and perspective

Don't worry too much about commenting

All comments are cherished

Debate on constructive criticism

Personally as this is a very personal thing. I am really happy with any review. I've gotten a couple that were rather critical and many others that were rather basic, some that could easily be a short essay and some that are just a couple words.

When giving them, I normally only read completed works myself so if I leave a review it will be on the last chapter. Just kind of a thank you for the read and such.

Thank you very must for the help. I will be looking at the links you enclosed in your answer.