its weighty themes are too grave for youngsters , 
(ROOT (S (NP (PRP$ its) (JJ weighty) (NNS themes)) (VP (VBP are) (ADJP (RB too) (JJ grave)) (PP (IN for) (NP (NNS youngsters)))) (, ,)))
(ROOT (S (NP (PRP$ ) (JJ ) (NNS )) (VP (VBP ) (ADJP (RB ) (JJ )) (PP (IN ) (NP (NNS )))) (, )))