Where is, where was this?
( ( Where is ) ( , ( where ( ( was this ) ? ) ) ) )
(ROOT (SBARQ (SBAR (WHADVP (WRB Where)) (S (VP (VBZ is)))) (, ,) (WHADVP (WRB where)) (SQ (VBD was) (NP (DT this))) (. ?)))
Where did it happen?
( Where ( ( ( did it ) happen ) ? ) )
(ROOT (SBARQ (WHADVP (WRB Where)) (SQ (VBD did) (NP (PRP it)) (VP (VB happen))) (. ?)))