I was old enough at the time that I knew what was going on.
( I ( ( was ( ( ( old enough ) ( at ( the time ) ) ) ( that ( I ( knew ( what ( was ( going on ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD was) (ADJP (ADJP (JJ old) (RB enough) (PP (IN at) (NP (DT the) (NN time)))) (SBAR (IN that) (S (NP (PRP I)) (VP (VBD knew) (SBAR (WHNP (WP what)) (S (VP (VBD was) (VP (VBG going) (PRT (RP on))))))))))) (. .)))
By that age, I knew what was happening.
( ( By ( that age ) ) ( , ( I ( ( knew ( what ( was happening ) ) ) . ) ) ) )
(ROOT (S (PP (IN By) (NP (DT that) (NN age))) (, ,) (NP (PRP I)) (VP (VBD knew) (SBAR (WHNP (WP what)) (S (VP (VBD was) (VP (VBG happening)))))) (. .)))