\\ How \\, how come?
( ( ( \ \ ) ( How ( \ \ ) ) ) ( , ( ( how come ) ? ) ) )
(ROOT (SBARQ (FRAG (NP (NNP \) (NNP \)) (WHADJP (WRB How) (ADJP (RB \) (JJ \)))) (, ,) (SBARQ (WHADVP (WRB how)) (SQ (VP (VBP come)))) (. ?)))
I don't care how you did it, I just want to know why? 
( ( I ( ( do n't ) ( care ( how ( you ( did it ) ) ) ) ) ) ( , ( I ( just ( ( want ( to ( know why ) ) ) ? ) ) ) ) )
(ROOT (S (S (NP (PRP I)) (VP (VBP do) (RB n't) (VP (VB care) (SBAR (WHADVP (WRB how)) (S (NP (PRP you)) (VP (VBD did) (NP (PRP it)))))))) (, ,) (NP (PRP I)) (ADVP (RB just)) (VP (VBP want) (S (VP (TO to) (VP (VB know) (SBARQ (WHADVP (WRB why))))))) (. ?)))