oh really yeah i've i've never seen either one of them
( oh ( really ( yeah ( i ( 've ( i ( ( 've never ) ( seen ( ( either one ) ( of them ) ) ) ) ) ) ) ) ) )
(ROOT (S (NP (NNP oh)) (VP (ADVP (RB really)) (VBP yeah) (SBAR (S (NP (FW i)) (VP (VBP 've) (NP (NP (FW i)) (SBAR (S (VP (VBP 've) (ADVP (RB never)) (VP (VBN seen) (NP (NP (DT either) (NN one)) (PP (IN of) (NP (PRP them)))))))))))))))
I've seen them both many times.
( I ( ( 've ( ( seen them ) ( both ( many times ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP 've) (VP (VBN seen) (NP (PRP them)) (NP (DT both) (JJ many) (NNS times)))) (. .)))