The air is warm.
( ( The air ) ( ( is warm ) . ) )
(ROOT (S (NP (DT The) (NN air)) (VP (VBZ is) (ADJP (JJ warm))) (. .)))
The frigid air caught them all by surprise.
( ( The ( frigid air ) ) ( ( ( caught them ) ( all ( by surprise ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ frigid) (NN air)) (VP (VBD caught) (NP (PRP them)) (PP (DT all) (IN by) (NP (NN surprise)))) (. .)))