free to go get popcorn whenever he 's not onscreen 
(ROOT (ADJP (JJ free) (S (VP (TO to) (VP (VB go) (VP (VB get) (NP (NN popcorn)) (SBAR (WHADVP (WRB whenever)) (S (NP (PRP he)) (VP (VBZ 's) (RB not) (ADJP (JJ onscreen)))))))))))
(ROOT (ADJP (JJ ) (S (VP (TO ) (VP (VB ) (VP (VB ) (NP (NN )) (SBAR (WHADVP (WRB )) (S (NP (PRP )) (VP (VBZ ) (RB ) (ADJP (JJ )))))))))))