the most notable observation is how long you 've been sitting still 
(ROOT (S (NP (DT the) (ADJP (RBS most) (JJ notable)) (NN observation)) (VP (VBZ is) (SBAR (WHADVP (WRB how) (RB long)) (S (NP (PRP you)) (VP (VBP 've) (VP (VBN been) (VP (VBG sitting) (ADVP (RB still))))))))))
(ROOT (S (NP (DT ) (ADJP (RBS ) (JJ )) (NN )) (VP (VBZ ) (SBAR (WHADVP (WRB ) (RB )) (S (NP (PRP )) (VP (VBP ) (VP (VBN ) (VP (VBG ) (ADVP (RB ))))))))))