( energy ( ( can ( be ( ( converted ( but not ) ) destroyed ) ) ) . ) )
(ROOT (S (NP (NN energy)) (VP (MD can) (VP (VB be) (VP (VBN converted) (CONJP (CC but) (RB not)) (VBN destroyed)))) (. .)))
energy can be converted but not destroyed.
(ROOT (S (NP (NNP Energy) (PRP it)) (VP (MD can) (RB not) (VP (VB be) (VP (VBN destroyed)))) (. .)))