could n't make a guest appearance to liven things up 
(ROOT (S (VP (MD could) (RB n't) (VP (VB make) (NP (DT a) (NN guest) (NN appearance)) (S (VP (TO to) (VP (VB liven) (NP (NNS things)) (PRT (RP up)))))))))
(ROOT (S (VP (MD ) (RB ) (VP (VB ) (NP (DT ) (NN ) (NN )) (S (VP (TO ) (VP (VB ) (NP (NNS )) (PRT (RP )))))))))