apple posted:[. . .] 3.Where are you cleaning? I’m cleaning the kitchen
[. . .]
What about sentences 3? “the kitchen” is the object of the sentence.
Is “where” grammatically acceptable as a question word?
Or is there a better interrogative sentence asking what part of the house, or which room is being cleaned?
The third example doesn't work. "I'm cleaning the kitchen" can be used in response to "What are you cleaning?" (or "What are you doing?") but not in response to "Where are you cleaning?"
You could ask "Where are you cleaning?" if you wanted a prepositional phrase or a free relative clause to the the focus of the answer. Then the idea would be that you are not cleaning the location but something else in the location.
A: Where are you cleaning the silverware?
B: I'm cleaning it in the kitchen.
A: Where are you cleaning your clarinet?
B: I'm cleaning it where I cleaned it the last time -- in the kitchen.