I know about that!
( I ( ( know ( about that ) ) ! ) )
(ROOT (S (NP (PRP I)) (VP (VBP know) (PP (IN about) (NP (DT that)))) (. !)))
I was the one that told you about that.
( I ( ( was ( ( the one ) ( that ( ( told you ) ( about that ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD was) (NP (NP (DT the) (NN one)) (SBAR (WHNP (WDT that)) (S (VP (VBD told) (NP (PRP you)) (PP (IN about) (NP (DT that)))))))) (. .)))