( ( The period ) ( ( is ( ( the time ) ( of ( one ( complete ( wave ( to pass ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN period)) (VP (VBZ is) (NP (NP (DT the) (NN time)) (PP (IN of) (NP (CD one) (JJ complete) (NN wave) (S (VP (TO to) (VP (VB pass)))))))) (. .)))
The period is the time of one complete wave to pass.
(ROOT (S (NP (NN Period)) (VP (VBZ is) (NP (NP (DT the) (NN time) (NN interval)) (VP (VBN required) (PP (IN for) (NP (CD one) (JJ complete) (NN wave) (S (VP (TO to) (VP (VB pass) (NP (NP (DT a) (NN point)) (VP (VBN called))))))))))) (. .)))