did you see it
( ( did you ) ( see it ) )
(ROOT (SINV (VBD did) (NP (PRP you)) (VP (VB see) (NP (PRP it)))))
There is nothing there.
( There ( ( ( is nothing ) there ) . ) )
(ROOT (S (NP (EX There)) (VP (VBZ is) (NP (NN nothing)) (ADVP (RB there))) (. .)))