( ( The tides ) ( ( are ( created ( by ( ( the ( gravitational pull ) ) ( of ( the ( ( moon and ) sun ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS tides)) (VP (VBP are) (VP (VBN created) (PP (IN by) (NP (NP (DT the) (JJ gravitational) (NN pull)) (PP (IN of) (NP (DT the) (NN moon) (CC and) (NN sun))))))) (. .)))
The tides are created by the gravitational pull of the moon and sun.
(ROOT (S (NP (NNP Spring) (NNS tides)) (VP (VBP are) (VP (VBN created) (SBAR (WHADVP (WRB when)) (S (NP (NP (DT the) (NN sun)) (CC and) (NP (NP (NN moon) (POS 's)) (NNS tides))) (VP (VBP match)))))) (. .)))