a native were because them could be .
(ROOT_0 (S_0 (ATS_3 (NP_1 (DT_0 a) (NN_2 native)) (VP_4 (VBD_0 were) (SBAR_0 (IN_2 because) (S_1 (NP_0 (PRP_0 them)) (VP_5 (MD_0 could) (VP_1 (VB_0 be))))))) (DOT_0 .)))