(S (S (SBAR (WHADVP (WRB When)) (S (BASENP (NNP Shankbone)) (VP (VBD arrived) (PP (IN on) (NP (BASENP (DT the) (JJ sixth) (NN floor)) (PP (IN of) (BASENP (DT a) (JJ midtown) (NN office) (NN building)))))))) (COMMA ,) (S (BASENP (DT the) (NN elevator)) (VP (VP (VBD opened) (PRT (RP up))) (PP (TO to) (NP (BASENP (DT a) (NN hallway)) (SBAR (WHADVP (WRB where)) (S (BASENP (DT a) (VBG smiling) (NNP Rebecca)) (VP (VBD greeted) (BASENP (PRP him)))))))))) (PERIOD .))