Is it correct to say "O henüz konuşuyor mu"?
henüz is typically used in negative sentences O henüz konuşmuyor: he is not talking yet
henüz can also mean "just": Henüz geldim = I just arrived/came
This is gramatically correct, but it does not make much sense in meaning.
"Is he still speaking?"
Translation: Hala konuşuyor mu?
O hala konuşuyor mu? - Is she still speaking?
I tried the other correct answer which was accepted by Duo.