doze off thirty minutes into the film 
(ROOT (S (VP (VB doze) (PRT (RP off)) (NP (NP (CD thirty) (NNS minutes)) (PP (IN into) (NP (DT the) (NN film)))))))
(ROOT (S (VP (VB ) (PRT (RP )) (NP (NP (CD ) (NNS )) (PP (IN ) (NP (DT ) (NN )))))))