Candle grease? 
( ( Candle grease ) ? )
(ROOT (SQ (VP (VB Candle) (NP (NN grease))) (. ?)))
Was it candle grease?
( ( ( Was it ) ( candle grease ) ) ? )
(ROOT (SQ (VBD Was) (NP (PRP it)) (NP (NN candle) (NN grease)) (. ?)))