( Electrical energy )
(ROOT (NP (JJ Electrical) (NN energy)))
Electrical energy
(ROOT (S (NP (NP (NNP Heat)) (, ,) (NP (NN light)) (, ,) (CC and) (NP (NN sound))) (VP (VBP are) (NP (NP (DT all) (JJ different) (NNS forms)) (PP (IN of) (NP (NN energy))))) (. .)))