The story
From the fact that many of the adverbs and pronouns that are used at the beginning of such sentences, such as what, when, which, who, and why, begin with wh.
Etymology from Wiktionary, CC BY-SA 4.0.
wh-question
wh-quest·ionToday it means: A question that is introduced by a wh-word (what, where, why, etc.) and cannot be answered by yes or no. Full definition →