I've thought it well over  "
( I ( 've ( ( ( thought it ) ( well over ) ) '' ) ) )
(ROOT (S (NP (PRP I)) (VP (VBP 've) (VP (VBN thought) (S (NP (PRP it))) (ADVP (RB well) (RB over)) ('' '')))))
I've been thinking about it for the past two weeks. 
( I ( ( 've ( been ( ( ( thinking about ) it ) ( for ( the ( past ( two weeks ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP 've) (VP (VBN been) (VP (VBG thinking) (IN about) (NP (PRP it)) (PP (IN for) (NP (DT the) (JJ past) (CD two) (NNS weeks)))))) (. .)))