A silver revolver.
( ( A silver ) ( revolver . ) )
(ROOT (S (NP (DT A) (NN silver)) (VP (VBP revolver)) (. .)))
There was no gun.
( There ( ( was ( no gun ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBD was) (NP (DT no) (NN gun))) (. .)))