Awkward title probably, but lemme explain:
The question is “This piece of French architecture was finished on January 26, 1887.” You know this is the Eiffel Tower. But when you buzz in and give the response, you say:
“Who is the Eiffel Tower?”
Would you be awarded the points for being correct, or docked the points for being incorrect since you didn’t say “WHAT is the Eiffel Tower?”
As others have already mentioned the response just has to be in the form of a question. If you forget in the first round you get a pass and a reminder to “remember your phrasing”. Then in double jeopardy if you forget, you’ll be ruled incorrect.
Another fun fact is that if the correct response is already in the form of a question, you don’t have to add anything. For instance “who’s afraid of virginia woolf?” would be accepted as a correct response.
I’ve also seen a few instances of people unintentionally posing a question and it being accepted. Something along the lines of “oh, uhhh, is it Edward Albee?”
Also the question doesn’t have to fit the clue. People often use “where is…” for places, but the clue is almost never describing the location of the place.