( ( In ( ( the ( first year ) ) ( of infancy ) ) ) ( , ( diagnosis ( ( is ( most difficult ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NP (DT the) (JJ first) (NN year)) (PP (IN of) (NP (NN infancy))))) (, ,) (NP (NN diagnosis)) (VP (VBZ is) (ADJP (RBS most) (JJ difficult))) (. .)))
In the first year of infancy, diagnosis is most difficult.
(ROOT (S (NP (NP (DT The) (JJ first) (NN year)) (PP (IN after) (NP (NN birth)))) (VP (VBZ is) (VP (VBN called) (NP (NN infancy)))) (. .)))