on boy do in before stones be sharp actions back .
(ROOT_0 (S_0 (ATS_3 (NP_1 (IN_2 on) (NN_3 boy)) (VP_4 (ATVP_1 (VBP_0 do) (PP_2 (IN_0 in) (PP_2 (IN_0 before) (NP_3 (NNS_1 stones))))) (VP_1 (ATVP_2 (VB_0 be) (NP_4 (JJ_1 sharp) (NNS_1 actions))) (ADVP_0 (RB_0 back))))) (DOT_0 .)))