He An air attack against North America may be in progress.
( He ( ( ( An ( air attack ) ) ( against ( North America ) ) ) ( ( may ( be ( in progress ) ) ) . ) ) )
(ROOT (S (NP (PRP He)) (PP (NP (DT An) (NN air) (NN attack)) (IN against) (NP (NNP North) (NNP America))) (VP (MD may) (VP (VB be) (PP (IN in) (NP (NN progress))))) (. .)))
The air attack was over.
( ( The ( air attack ) ) ( ( was over ) . ) )
(ROOT (S (NP (DT The) (NN air) (NN attack)) (VP (VBD was) (ADJP (RP over))) (. .)))