marks a modest if encouraging return to form 
(ROOT (S (VP (VBZ marks) (NP (NP (DT a) (ADJP (JJ modest) (IN if) (VBG encouraging)) (NN return)) (PP (IN to) (NP (NN form)))))))
(ROOT (S (VP (VBZ ) (NP (NP (DT ) (ADJP (JJ ) (IN ) (VBG )) (NN )) (PP (IN ) (NP (NN )))))))