And that's why I'm writing to you today.
( And ( that ( ( 's ( why ( I ( 'm ( ( writing ( to you ) ) today ) ) ) ) ) . ) ) )
(ROOT (S (CC And) (NP (DT that)) (VP (VBZ 's) (SBAR (WHADVP (WRB why)) (S (NP (PRP I)) (VP (VBP 'm) (VP (VBG writing) (PP (TO to) (NP (PRP you))) (NP (NN today))))))) (. .)))
That is why I am writing you on this day.
( That ( ( is ( why ( I ( am ( ( writing you ) ( on ( this day ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT That)) (VP (VBZ is) (SBAR (WHADVP (WRB why)) (S (NP (PRP I)) (VP (VBP am) (VP (VBG writing) (NP (PRP you)) (PP (IN on) (NP (DT this) (NN day)))))))) (. .)))