What's your favorite?
( What ( ( 's ( your favorite ) ) ? ) )
(ROOT (SBARQ (WHNP (WP What)) (SQ (VBZ 's) (NP (PRP$ your) (NN favorite))) (. ?)))
Which on do you like the least?
( ( Which on ) ( ( ( do you ) ( like ( the least ) ) ) ? ) )
(ROOT (SBARQ (WHNP (WHNP (WDT Which)) (PP (IN on))) (SQ (VBP do) (NP (PRP you)) (VP (VB like) (NP (DT the) (JJS least)))) (. ?)))