their personalities undergo radical changes when it suits the script 
(ROOT (S (NP (PRP$ their) (NNS personalities)) (VP (VBP undergo) (NP (JJ radical) (NNS changes)) (SBAR (WHADVP (WRB when)) (S (NP (PRP it)) (VP (VBZ suits) (NP (DT the) (NN script))))))))
(ROOT (S (NP (PRP$ ) (NNS )) (VP (VBP ) (NP (JJ ) (NNS )) (SBAR (WHADVP (WRB )) (S (NP (PRP )) (VP (VBZ ) (NP (DT ) (NN ))))))))