i 'll go out on a limb . 
(ROOT (S (NP (PRP i)) (VP (MD 'll) (VP (VB go) (ADVP (RB out)) (PP (IN on) (NP (DT a) (NN limb))))) (. .)))
(ROOT (S (NP (PRP )) (VP (MD ) (VP (VB ) (ADVP (RB )) (PP (IN ) (NP (DT ) (NN ))))) (. )))