spent watching this waste of time . 
(ROOT (S (VP (VBD spent) (S (VP (VBG watching) (NP (NP (DT this) (NN waste)) (PP (IN of) (NP (NN time))))))) (. .)))
(ROOT (S (VP (VBD ) (S (VP (VBG ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (NN ))))))) (. )))