( Evaporation ( ( is ( ( the change ) ( of ( state ( of ( ( water ( -LRB- ( ( a liquid ) -RRB- ) ) ) ( to ( water ( vapor ( -LRB- ( ( a gas ) -RRB- ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Evaporation)) (VP (VBZ is) (NP (NP (DT the) (NN change)) (PP (IN of) (NP (NP (NN state)) (PP (IN of) (NP (NN water) (PRN (-LRB- -LRB-) (NP (DT a) (NN liquid)) (-RRB- -RRB-)) (S (VP (TO to) (VP (VB water) (NP (NP (NN vapor)) (PRN (-LRB- -LRB-) (NP (DT a) (NN gas)) (-RRB- -RRB-)))))))))))) (. .)))
Evaporation is the change of state of water (a liquid) to water vapor (a gas).
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (JJ liquid) (NN water) (NNS changes)) (VP (TO to) (VP (VB water) (NP (NN vapor)))))) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (NP (NN evaporation)))) (. .)))
When liquid water changes to water vapor it is called evaporation.