She leaned back in her chair.
( She ( ( ( leaned back ) ( in ( her chair ) ) ) . ) )
(ROOT (S (NP (PRP She)) (VP (VBD leaned) (ADVP (RB back)) (PP (IN in) (NP (PRP$ her) (NN chair)))) (. .)))
She was sitting on a red chair. 
( She ( ( was ( sitting ( on ( a ( red chair ) ) ) ) ) . ) )
(ROOT (S (NP (PRP She)) (VP (VBD was) (VP (VBG sitting) (PP (IN on) (NP (DT a) (JJ red) (NN chair))))) (. .)))