Oh I've done that a number of times.
( Oh ( I ( ( 've ( done ( that ( ( a number ) ( of times ) ) ) ) ) . ) ) )
(ROOT (S (ADVP (RB Oh)) (NP (PRP I)) (VP (VBP 've) (VP (VBN done) (PP (IN that) (NP (NP (DT a) (NN number)) (PP (IN of) (NP (NNS times))))))) (. .)))
I've done that many times.
( I ( ( 've ( done ( that ( many times ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP 've) (VP (VBN done) (NP (DT that) (JJ many) (NNS times)))) (. .)))