it could have been something special 
(ROOT (S (NP (PRP it)) (VP (MD could) (VP (VB have) (VP (VBN been) (NP (NN something) (JJ special)))))))
(ROOT (S (NP (PRP )) (VP (MD ) (VP (VB ) (VP (VBN ) (NP (NN ) (JJ )))))))