I didn't hit nothing.
( I ( ( ( did n't ) ( hit nothing ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD did) (RB n't) (VP (VB hit) (NP (NN nothing)))) (. .)))
I hit the vase.
( I ( ( hit ( the vase ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD hit) (NP (DT the) (NN vase))) (. .)))