( ( ( ( ( ( ( ( ( The ( term ( `` ( potential ( energy '' ) ) ) ) ) ( -LRB- ( ( energy ( due ( to ( ( position or ) configuration ) ) ) ) -RRB- ) ) ) ( ( is not ) necessary ) ) , ) but ) ( ( if ( one ( does ( want ( to ( use it ) ) ) ) ) ) ( then ( there ( are ( ( five ( potential forms ) ) ( of energy ) ) ) ) ) ) ) : ) ( ( gravitational ( , ( ( ( ( ( ( ( ( elastic , ) electromagnetic ) , ) chemical ) , ) and ) nuclear ) . ) ) ) ( ( The ( unqualified term ) ) ( ( `` ( potential ( energy '' ) ) ) ( can ( be ambiguous ) ) ) ) ) ) . )
(ROOT (S (S (S (NP (NP (DT The) (NN term) (`` ``) (NN potential) (NN energy) ('' '')) (PRN (-LRB- -LRB-) (S (NP (NN energy)) (ADJP (JJ due) (PP (TO to) (NP (NN position) (CC or) (NN configuration))))) (-RRB- -RRB-))) (VP (VBZ is) (RB not) (ADJP (JJ necessary)))) (, ,) (CC but) (S (SBAR (IN if) (S (NP (PRP one)) (VP (VBZ does) (VP (VB want) (S (VP (TO to) (VP (VB use) (NP (PRP it))))))))) (ADVP (RB then)) (NP (EX there)) (VP (VBP are) (NP (NP (CD five) (JJ potential) (NNS forms)) (PP (IN of) (NP (NN energy))))))) (: :) (X (X (ADVP (RB gravitational)) (, ,) (NP (NP (NN elastic)) (, ,) (NP (NN electromagnetic)) (, ,) (NP (NN chemical)) (, ,) (CC and) (NP (JJ nuclear))) (. .)) (NP (NP (DT The) (JJ unqualified) (NN term)) (SBAR (S (NP (`` ``) (JJ potential) (NN energy) ('' '')) (VP (MD can) (VP (VB be) (ADJP (JJ ambiguous)))))))) (. .)))
The term "potential energy" (energy due to position or configuration) is not necessary, but if one does want to use it then there are five potential forms of energy:  gravitational, elastic, electromagnetic, chemical, and nuclear.  The unqualified term "potential energy" can be ambiguous.
(ROOT (S (NP (DT The) (ADJP (NN term) (JJ elastic)) (JJ potential) (NN energy)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB describe) (S (NP (JJ potential) (NN energy)) (ADJP (JJ due) (PP (TO to) (NP (NP (DT an) (NN object) (POS 's)) (NN shape)))))))))) (. .)))