Candle grease? 
( ( Candle grease ) ? )
(ROOT (SQ (VP (VB Candle) (NP (NN grease))) (. ?)))
It was not candle grease.
( It ( ( ( was not ) ( candle grease ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBD was) (RB not) (NP (NN candle) (NN grease))) (. .)))