( ( Condensation ( The ( invisible ( water vapor ) ) ) ) ( ( ( gathers together ) ( as ( it ( ( cools and ) ( condenses ( to ( form ( a cloud ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Condensation)) (NP (DT The) (JJ invisible) (NN water) (NN vapor))) (VP (VBZ gathers) (PRT (RP together)) (SBAR (IN as) (S (NP (PRP it)) (VP (VP (VBZ cools)) (CC and) (VP (VBZ condenses) (S (VP (TO to) (VP (VB form) (NP (DT a) (NN cloud)))))))))) (. .)))
Condensation The invisible water vapor gathers together as it cools and condenses to form a cloud.
(ROOT (S (NP (NNP Condensation)) (VP (MD must) (VP (VB occur) (PP (IN for) (NP (NNS clouds))) (S (VP (TO to) (VP (VB form)))))) (. .)))