by an adult who 's apparently been forced by his kids to watch too many barney videos 
(ROOT (PP (IN by) (NP (NP (DT an) (NN adult)) (SBAR (WHNP (WP who)) (S (VP (VBZ 's) (ADVP (RB apparently)) (VP (VBN been) (VP (VBN forced) (PP (IN by) (NP (PRP$ his) (NNS kids))) (S (VP (TO to) (VP (VB watch) (NP (ADJP (RB too) (JJ many)) (NN barney) (NNS videos)))))))))))))
(ROOT (PP (IN ) (NP (NP (DT ) (NN )) (SBAR (WHNP (WP )) (S (VP (VBZ ) (ADVP (RB )) (VP (VBN ) (VP (VBN ) (PP (IN ) (NP (PRP$ ) (NNS ))) (S (VP (TO ) (VP (VB ) (NP (ADJP (RB ) (JJ )) (NN ) (NNS )))))))))))))