( Clouds ( ( form ( when ( ( water vapor ) ( ( ( condenses ( around ( small particles ) ) ) , ) ( like ( bits ( of ( ( ( dust or ) smoke ) ( in ( the air ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Clouds)) (VP (VBP form) (SBAR (WHADVP (WRB when)) (S (NP (NN water) (NN vapor)) (VP (VBZ condenses) (PP (IN around) (NP (JJ small) (NNS particles))) (, ,) (PP (IN like) (NP (NP (NNS bits)) (PP (IN of) (NP (NP (NN dust) (CC or) (NN smoke)) (PP (IN in) (NP (DT the) (NN air))))))))))) (. .)))
Clouds form when water vapor condenses around small particles, like bits of dust or smoke in the air.
(ROOT (S (VP (VB Clouds) (NP (NP (NN form)) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-)) (SBAR (WHADVP (WRB when)) (S (NP (NN water) (NN vapor)) (VP (VBZ condenses) (PP (IN in) (NP (NP (DT the) (NN air)) (PP (IN around) (NP (NP (NNS specs)) (PP (IN of) (NP (NN matter)))))))))))) (. .)))