I could ask the surfer before forward .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 I)) (VP_4 (MD_0 could) (VP_1 (VB_0 ask) (NP_3 (NP_5 (DT_0 the) (NN_2 surfer)) (PP_0 (IN_1 before) (NP_2 (RB_0 forward))))))) (DOT_0 .)))