( ( Ocean ( Waves Waves ) ) ( ( are ( generated ( by ( winds ( that ( ( blow over ) ( ( the surface ) ( of oceans ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Ocean) (NNPS Waves) (NNP Waves)) (VP (VBP are) (VP (VBN generated) (PP (IN by) (NP (NP (NNS winds)) (SBAR (WHNP (WDT that)) (S (VP (VB blow) (PRT (RP over)) (NP (NP (DT the) (NN surface)) (PP (IN of) (NP (NNS oceans))))))))))) (. .)))
Ocean Waves Waves are generated by winds that blow over the surface of oceans.
(ROOT (S (NP (NNP Ocean) (NNS waves)) (VP (VBP are) (ADVP (RB mainly)) (VP (VBN caused) (PP (IN by) (NP (NN wind))))) (. .)))