you 've seen it all before 
(ROOT (S (NP (PRP you)) (VP (VBP 've) (VP (VBN seen) (NP (NP (PRP it)) (NP (DT all))) (ADVP (RB before))))))
(ROOT (S (NP (PRP )) (VP (VBP ) (VP (VBN ) (NP (NP (PRP )) (NP (DT ))) (ADVP (RB ))))))