( ( The ( water vapor ) ) ( ( forms ( ( ( ( a cloud ) and ) ( the particles ) ) ( can ( ( ( act ( as ( cloud ( condensation nuclei ) ) ) ) , ) ( meaning ( they ( attract water ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN water) (NN vapor)) (VP (VBZ forms) (SBAR (S (NP (NP (DT a) (NN cloud)) (CC and) (NP (DT the) (NNS particles))) (VP (MD can) (VP (VB act) (PP (IN as) (NP (NN cloud) (NN condensation) (NNS nuclei))) (, ,) (S (VP (VBG meaning) (S (NP (PRP they)) (VP (VB attract) (NP (NN water))))))))))) (. .)))
The water vapor forms a cloud and the particles can act as cloud condensation nuclei, meaning they attract water.
(ROOT (S (NP (NNP Water) (NN vapor)) (VP (MD must) (VP (VB lose) (NP (NN heat) (NN energy)) (SBAR (IN before) (S (NP (NNS clouds)) (VP (MD can) (VP (VB form))))))) (. .)))
Water vapor must lose heat energy before clouds can form.