to do that is really funny 
(ROOT (S (S (VP (TO to) (VP (VB do) (NP (DT that))))) (VP (VBZ is) (ADJP (RB really) (JJ funny)))))
(ROOT (S (S (VP (TO ) (VP (VB ) (NP (DT ))))) (VP (VBZ ) (ADJP (RB ) (JJ )))))