Using never in interrogative sentences

I would use ever rather than never. Also I'd leave off yet.

Better still ... I'd say:

Have you not read the letter yet?

thanks for ur reply.is that wrong to use never. why we can say havent you read the letter yet but we cant say have you never read the letter yet

Not colloquial. Technically don't know if correct, but "never" and "yet" strike one as redundant. We'd say instead:

"Have you not read the letter yet?" or
"Haven't you read the letter yet?"

…..though you can omit "yet" as redundant

"Have you never read the letter?" is probably okay, while

"You never read the letter?" is also colloquial

Him: Wow, look at that beautiful building!
Her: Have you never seen that before? It's been here for over 120 years.

Only though, as you suggest, omitting "yet"

The "yet" seems unnecessary Har, or redundant

what about : I have never read a book yet. is yet still redundant. Thanks

No. "I have never read a book" means just what it says. "I have never read a book yet" kind of implies you might read a book sometime in the future.

Personally, I would more likely say "I have not read a book"

Roger is right, the "yet" implies an intention someday, but awkward. Better, "I haven't yet read a book"