with an avid interest in the subject 
(ROOT (PP (IN with) (NP (NP (DT an) (JJ avid) (NN interest)) (PP (IN in) (NP (DT the) (NN subject))))))
(ROOT (PP (IN ) (NP (NP (DT ) (JJ ) (NN )) (PP (IN ) (NP (DT ) (NN ))))))