"Is the book terrible?"
Translation:Er boken forferdelig?
If this sentence was posed as a statement it would be "Boken er forferdelig." This is a typical predicative expression, and would describe "en forferdelig bok" (a terrible book). Now, when you pose a question, you would put the verb before the subject, just as in the original sentence. So it's not a case of putting the adjective after the noun, but putting the verb before the noun in this case.