( ( ( Only ( four percent ) ) ( of ( ( the ( electrical energy ) ) ( reaching ( the ( light bulb ) ) ) ) ) ) ( ( is ( converted ( into light ) ) ) . ) )
(ROOT (S (NP (NP (RB Only) (CD four) (NN percent)) (PP (IN of) (NP (NP (DT the) (JJ electrical) (NN energy)) (VP (VBG reaching) (NP (DT the) (JJ light) (NN bulb)))))) (VP (VBZ is) (VP (VBN converted) (PP (IN into) (NP (NN light))))) (. .)))
Only four percent of the electrical energy reaching the light bulb is converted into light.
(ROOT (S (NP (DT A) (JJ light) (NN bulb)) (VP (VBZ converts) (NP (JJ electrical) (NN energy)) (PP (TO to) (NP (JJ light) (CC and) (JJ thermal) (NN energy)))) (. .)))