is never able to pull it back on course . 
(ROOT (S (VP (VBZ is) (ADVP (RB never)) (ADJP (JJ able) (S (VP (TO to) (VP (VB pull) (NP (PRP it)) (ADVP (RB back) (PP (IN on) (NP (NN course))))))))) (. .)))
(ROOT (S (VP (VBZ ) (ADVP (RB )) (ADJP (JJ ) (S (VP (TO ) (VP (VB ) (NP (PRP )) (ADVP (RB ) (PP (IN ) (NP (NN ))))))))) (. )))