ca n't help but engage an audience 
(ROOT (S (VP (MD ca) (RB n't) (VP (VB help) (CC but) (VP (VB engage) (NP (DT an) (NN audience)))))))
(ROOT (S (VP (MD ) (RB ) (VP (VB ) (CC ) (VP (VB ) (NP (DT ) (NN )))))))