I know about that!
( I ( ( know ( about that ) ) ! ) )
(ROOT (S (NP (PRP I)) (VP (VBP know) (PP (IN about) (NP (DT that)))) (. !)))
I never knew that!
( I ( never ( ( knew that ) ! ) ) )
(ROOT (S (NP (PRP I)) (ADVP (RB never)) (VP (VBD knew) (NP (DT that))) (. !)))