( ( When ( ( ( ( the moon ) and ) ( the sun ) ) ( are ( ( working together ) ( to ( make ( ( very big ) tides ) ) ) ) ) ) ) ( , ( ( the effect ) ( ( is ( called ( Spring Tides ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (DT the) (NN moon)) (CC and) (NP (DT the) (NN sun))) (VP (VBP are) (VP (VBG working) (ADVP (RB together)) (S (VP (TO to) (VP (VB make) (NP (ADJP (RB very) (JJ big)) (NNS tides))))))))) (, ,) (NP (DT the) (NN effect)) (VP (VBZ is) (VP (VBN called) (NP (NNP Spring) (NNP Tides)))) (. .)))
When the moon and the sun are working together to make very big tides, the effect is called Spring Tides.
(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)))))) (. .)))