difficult to tell who the other actors in the movie are 
(ROOT (ADJP (JJ difficult) (S (VP (TO to) (VP (VB tell) (SBAR (WHNP (WP who)) (S (NP (NP (DT the) (JJ other) (NNS actors)) (PP (IN in) (NP (DT the) (NN movie)))) (VP (VBP are)))))))))
(ROOT (ADJP (JJ ) (S (VP (TO ) (VP (VB ) (SBAR (WHNP (WP )) (S (NP (NP (DT ) (JJ ) (NNS )) (PP (IN ) (NP (DT ) (NN )))) (VP (VBP )))))))))