( This ( ( stored ( energy ( is ( called ( potential energy ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBD stored) (SBAR (S (NP (NN energy)) (VP (VBZ is) (VP (VBN called) (NP (JJ potential) (NN energy))))))) (. .)))
This stored energy is   called potential energy.
(ROOT (S (NP (NP (NNP Energy)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN stored) (PP (IN in) (NP (DT a) (NN person) (CC or) (NN object)))))))) (VP (VBZ is) (VP (VBN called) (NP (JJ potential) (NN energy)))) (. .)))