nothing i had n't already seen . 
(ROOT (NP (NP (NN nothing)) (SBAR (S (NP (PRP i)) (VP (VBD had) (RB n't) (ADVP (RB already)) (VP (VBN seen))))) (. .)))
(ROOT (NP (NP (NN )) (SBAR (S (NP (PRP )) (VP (VBD ) (RB ) (ADVP (RB )) (VP (VBN ))))) (. )))