( ( The pH ) ( ( is ( ( a measurement ) ( of ( ( the acidity ) ( of water ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN pH)) (VP (VBZ is) (NP (NP (DT a) (NN measurement)) (PP (IN of) (NP (NP (DT the) (NN acidity)) (PP (IN of) (NP (NN water))))))) (. .)))
The pH is a measurement of the acidity of water.
(ROOT (S (NP (NP (DT The) (NN acidity)) (PP (IN of) (NP (DT a) (NN solution)))) (VP (VBZ is) (ADVP (RB typically)) (VP (VBN assessed) (ADVP (RB experimentally)) (PP (IN by) (NP (NP (NN measurement)) (PP (IN of) (NP (PRP$ its) (NN ph.)))))))))