will indeed sit open-mouthed before the screen , not screaming but yawning . 
(ROOT (S (VP (MD will) (ADVP (RB indeed)) (VP (VB sit) (S (ADJP (JJ open) (HYPH -) (VBN mouthed))) (PP (IN before) (NP (DT the) (NN screen))) (, ,) (S (RB not) (VP (VBG screaming) (CC but) (VP (VBG yawning)))))) (. .)))
(ROOT (S (VP (MD ) (ADVP (RB )) (VP (VB ) (S (ADJP (JJ ) (HYPH ) (VBN ))) (PP (IN ) (NP (DT ) (NN ))) (, ) (S (RB ) (VP (VBG ) (CC ) (VP (VBG )))))) (. )))