certainly not a good movie , but it was n't horrible either . 
(ROOT (S (FRAG (ADVP (RB certainly)) (RB not) (NP (DT a) (JJ good) (NN movie))) (, ,) (CC but) (S (NP (PRP it)) (VP (VBD was) (RB n't) (ADJP (JJ horrible)) (ADVP (RB either)))) (. .)))
(ROOT (S (FRAG (ADVP (RB )) (RB ) (NP (DT ) (JJ ) (NN ))) (, ) (CC ) (S (NP (PRP )) (VP (VBD ) (RB ) (ADJP (JJ )) (ADVP (RB )))) (. )))