He had forgotten about Adrin.
( He ( ( had ( forgotten ( about Adrin ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VBD had) (VP (VBN forgotten) (PP (IN about) (NP (NNP Adrin))))) (. .)))
He didn't remember Adrin.
( He ( ( ( did n't ) ( remember Adrin ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VBD did) (RB n't) (VP (VB remember) (NP (NNP Adrin)))) (. .)))