He should then captivated doing on classes .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 He)) (VP_4 (ATVP_1 (MD_0 should) (ADVP_0 (RB_0 then))) (VP_5 (VBD_2 captivated) (S_2 (VP_0 (VBG_0 doing) (PP_2 (IN_0 on) (NP_3 (NNS_1 classes)))))))) (DOT_0 .)))