want to smash its face in 
(ROOT (S (VP (VB want) (S (VP (TO to) (VP (VB smash) (NP (PRP$ its) (NN face)) (PRT (RP in))))))))
(ROOT (S (VP (VB ) (S (VP (TO ) (VP (VB ) (NP (PRP$ ) (NN )) (PRT (RP ))))))))