Why is the sentence horrible? vs Why the sentence is horrible?

English as a Second Language English Vocabulary, Grammar and Idioms
#1
  1. Why is the sentence horrible?
  2. Why the sentence is horrible?
    Is #2 correct?
    If both are correct, which one is better?
#2

A normal (asserive/declarative) sentence will be in the Subject - Verb order. But a question (interrogative) sentence will admit of only the Verb-subject order.

She is a student. (She = subject and is = verb; so it is in the SV order)
Is she a student? (Is = Verb and she = subject; VS order)

Why is the sentence horrible? (is = verb and the sentence = subject; VS order and hence a grammatically correct question)

Why the sentence is horrible? (the sentence = subject and is = verb; SV order, which is not accepted as a question)

However, in informal conversational contexts, with the help of a rising intonation, you are able to indicate the second sentence (Why the sentence is horrible?) as a question.

#3

Thanks a lot, Lawrence!
I thought that “Why the sentence is horrible?” was a perfectly correct question.