He watched the river flow.
( He ( ( watched ( the ( river flow ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VBD watched) (NP (DT the) (NN river) (NN flow))) (. .)))
The riverbed was completely dry.
( ( The riverbed ) ( ( was ( completely dry ) ) . ) )
(ROOT (S (NP (DT The) (NN riverbed)) (VP (VBD was) (ADJP (RB completely) (JJ dry))) (. .)))