his girl friday , '' maintaining a light touch while tackling serious themes 
(ROOT (S (NP (PRP$ his) (NN girl) (NNP friday)) (, ,) ('' '') (S (VP (VBG maintaining) (NP (DT a) (JJ light) (NN touch)) (SBAR (IN while) (S (VP (VBG tackling) (NP (JJ serious) (NNS themes)))))))))
(ROOT (S (NP (PRP$ ) (NN ) (NNP )) (, ) ('' ) (S (VP (VBG ) (NP (DT ) (JJ ) (NN )) (SBAR (IN ) (S (VP (VBG ) (NP (JJ ) (NNS )))))))))