I smiled vaguely.
( I ( ( smiled vaguely ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD smiled) (NP (NNS vaguely))) (. .)))
I was feeling sure of myself.
( I ( ( was ( feeling ( sure ( of myself ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD was) (VP (VBG feeling) (ADJP (JJ sure) (PP (IN of) (NP (PRP myself)))))) (. .)))