( Only ( they ( ( turn ( ( ( ( wheels , ) ( cause change ) ) or ) movement ) ) . ) ) )
(ROOT (S (RB Only) (NP (PRP they)) (VP (VBP turn) (NP (NP (NNS wheels)) (, ,) (NP (NN cause) (NN change)) (CC or) (NP (NN movement)))) (. .)))
Only they turn wheels, cause change or movement.
(ROOT (S (NP (DT The) (NN turning) (NN driveshaft)) (VP (VBZ causes) (NP (NP (DT the) (NNS wheels)) (PP (IN of) (NP (DT the) (NN car) (S (VP (TO to) (VP (VB turn)))))))) (. .)))
The turning driveshaft causes the wheels of the car to turn.