He came to teach had back then .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 He)) (VP_4 (VBD_2 came) (S_2 (VP_0 (TO_0 to) (VP_1 (VB_0 teach) (VP_2 (ATVP_2 (VBD_2 had) (PRT_0 (RP_0 back))) (ADVP_0 (RB_0 then)))))))) (DOT_0 .)))