has really done his subject justice . 
(ROOT (S (VP (VBZ has) (ADVP (RB really)) (VP (VBN done) (NP (PRP$ his) (NN subject)) (NP (NN justice)))) (. .)))
(ROOT (S (VP (VBZ ) (ADVP (RB )) (VP (VBN ) (NP (PRP$ ) (NN )) (NP (NN )))) (. )))