Definition
“A sentence that asks a question or makes a request for information.”
Cambridge University Press. "Interrogative Sentence." Cambridge Dictionary, 2022, dictionary.cambridge.org/us/dictionary/english/interrogative-sentence. Accessed 6 Sept. 2022.
Informal Definition
An interrogative sentence is a type of sentence that asks a question. They are typically marked by inversion of the subject and predicate. That means that the first verb in a verb phrase appears before the subject. A tell tale sign of an interrogative sentence is that the sentence ends with a question mark. Interrogative sentences can be both direct and indirect.
Example: "Are you a good witch or a bad witch?" -- Glinda, the Good Witch of the North, in The Wizard of Oz (1939)
Norquist, Richard. "Interrogative Sentences." ThoughtCo, 5 Feb. 2020, www.thoughtco.com/what-is-an-interrogative-sentence-1691183. Accessed 6 Sept. 2022.
Etymology
Early 16th cent.: from late Latin interrogativus, from Latin interrogare, from inter- ‘between’ + rogare ‘ask’.
Oxford University Press, editor. "Interrogative." Oxford Learner's Dictionary, 2022, www.oxfordlearnersdictionaries.com/us/definition/english/interrogative_1. Accessed 6 Sept. 2022.