we 've seen it all before in one form or another , 
(ROOT (S (NP (PRP we)) (VP (VBP 've) (VP (VBN seen) (NP (NP (PRP it)) (NP (DT all))) (ADVP (RB before)) (PP (IN in) (NP (NP (CD one) (NN form)) (CC or) (NP (DT another)))))) (, ,)))
(ROOT (S (NP (PRP )) (VP (VBP ) (VP (VBN ) (NP (NP (PRP )) (NP (DT ))) (ADVP (RB )) (PP (IN ) (NP (NP (CD ) (NN )) (CC ) (NP (DT )))))) (, )))