when you doze off thirty minutes into the film 
(ROOT (SBAR (WHADVP (WRB when)) (S (NP (PRP you)) (VP (VBP doze) (PRT (RP off)) (NP (NP (CD thirty) (NNS minutes)) (PP (IN into) (NP (DT the) (NN film))))))))
(ROOT (SBAR (WHADVP (WRB )) (S (NP (PRP )) (VP (VBP ) (PRT (RP )) (NP (NP (CD ) (NNS )) (PP (IN ) (NP (DT ) (NN ))))))))