, i ca n't compare friday after next to them 
(ROOT (S (, ,) (NP (PRP i)) (VP (MD ca) (RB n't) (VP (VB compare) (NP (NP (NNP friday)) (PP (RB after) (ADVP (RB next)))) (PP (IN to) (NP (PRP them)))))))
(ROOT (S (, ) (NP (PRP )) (VP (MD ) (RB ) (VP (VB ) (NP (NP (NNP )) (PP (RB ) (ADVP (RB )))) (PP (IN ) (NP (PRP )))))))