i'm not exactly sure
( i ( ( 'm not ) ( exactly sure ) ) )
(ROOT (S (NP (FW i)) (VP (VBP 'm) (RB not) (ADJP (RB exactly) (JJ sure)))))
I'm completely sure.
( I ( ( 'm ( completely sure ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP 'm) (ADJP (RB completely) (JJ sure))) (. .)))