( ( The river ) ( ( ( is commonly ) ( divided ( into ( three stages ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN river)) (VP (VBZ is) (ADVP (RB commonly)) (VP (VBN divided) (PP (IN into) (NP (CD three) (NNS stages))))) (. .)))
The river is commonly divided into three stages.
(ROOT (S (NP (NNP Adulthood)) (VP (VBZ is) (VP (VBN divided) (PP (IN into) (NP (CD three) (NNS stages))))) (. .)))