( There ( ( are ( ( ( ( two types ) ( of ( potential energies ) ) ) , ) ( ( gravitational and ) elastic ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD two) (NNS types)) (PP (IN of) (NP (JJ potential) (NNS energies))) (, ,) (ADJP (JJ gravitational) (CC and) (JJ elastic)))) (. .)))
There are two types of potential energies, gravitational and elastic.
(ROOT (S (S (VP (VBG Changing) (NP (NP (DT the) (NN shape)) (PP (IN of) (NP (DT an) (JJ elastic) (NN material)))))) (VP (VBZ gives) (NP (PRP it)) (NP (JJ potential) (NN energy))) (. .)))