open-mouthed before the screen , not screaming but yawning 
(ROOT (S (ADJP (ADJP (JJ open) (HYPH -) (JJ mouthed)) (PP (IN before) (NP (DT the) (NN screen)))) (, ,) (S (RB not) (VP (VBG screaming))) (CC but) (NP (NN yawning))))
(ROOT (S (ADJP (ADJP (JJ ) (HYPH ) (JJ )) (PP (IN ) (NP (DT ) (NN )))) (, ) (S (RB ) (VP (VBG ))) (CC ) (NP (NN ))))