( Voltage ( ( measures ( ( the energy ) ( per charge ) ) ) . ) )
(ROOT (S (NP (NNP Voltage)) (VP (VBZ measures) (NP (NP (DT the) (NN energy)) (PP (IN per) (NP (NN charge))))) (. .)))
Voltage measures the energy per charge.
(ROOT (S (NP (NNP Voltage)) (VP (VP (VBZ is) (RB not) (NP (NP (DT the) (JJ same)) (PP (IN as) (NP (NN energy))))) (, ,) (CC but) (VP (VBZ means) (NP (NP (DT the) (NN energy)) (PP (IN per) (NP (NN unit) (NN charge)))))) (. .)))