(S (S (BASENP (PRP They)) (VP (VBP say) (SBAR (SBAR (IN that) (S (BASENP (PRP it)) (VP (VP (VBZ is) (ADJP (RB too) (JJ difficult))) (S (VP (TO to) (VP (VB say) (SBAR (WHNP (WP what)) (S (BASENP (DT the) (NNS witnesses)) (VP (VBD saw)))))))))) (CONJP (COMMA ,) (CC but)) (SBAR (IN that) (S (NP (EX there)) (VP (VP (VBD was) (BASENP (PRP something))) (ADVP (RB there)))))))) (PERIOD .))