It is a commonplace that the grammatical form of a sentence is no sure guide to its logical form or to the ontological structure of the chunk of reality the sentence is about, if anything. For example, 'Kato Kaelin is home' and 'Nobody is home' are grammatically similar. They both seem to have the structure: singular subject/copula/predicate. But logically they are distinct: the first is singular, being about Kato Kaelin, America's most famous houseguest, while the second is existentially general. The second (standardly interpreted) is not about some dude named 'Nobody.' What is says is that it is not the
case that there exists a person x such that x is at home. It is not about any particular person.
So grammatical form and logical form need not coincide.
It interests me (and may even interest you) that one can make both affirmative and negative assertions using sentences in the interrogative mood. What is grammatically interrogative need not be logically interrogative.
Suppose someone asks whether God exists. A convinced theist can answer in the affirmative by uttering a grammatically interrogative sentence, for example, 'Is the Pope Catholic?' An adamant atheist can answer in the negative by a similar means: 'Is there an angry unicorn on the dark side of the moon?' (Example from Edward 'Cactus Ed' Abbey.)
Thus in this situation the theist expresses the indicative proposition that God exists by uttering the interrogative form of words, 'Is the Pope Catholic?' while the atheist expresses the indicative proposition that God does not exist by uttering the interrogative form of words, 'Is there an angry unicorn on the dark side of the moon?'
How labile the lapping of language upon the littoral of logic!