a highly gifted 12-year-old instead of a grown man 
(ROOT (NP (NP (DT a) (ADJP (RB highly) (VBN gifted)) (ADJP (NP (CD 12) (HYPH -) (NN year)) (HYPH -) (JJ old))) (PP (RB instead) (IN of) (NP (DT a) (VBN grown) (NN man)))))
(ROOT (NP (NP (DT ) (ADJP (RB ) (VBN )) (ADJP (NP (CD ) (HYPH ) (NN )) (HYPH ) (JJ ))) (PP (RB ) (IN ) (NP (DT ) (VBN ) (NN )))))