hit on a 15-year old when you 're over 100 
(ROOT (S (VP (VBD hit) (PP (IN on) (NP (DT a) (NML (CD 15) (HYPH -) (NN year)) (JJ old))) (SBAR (WHADVP (WRB when)) (S (NP (PRP you)) (VP (VBP 're) (PP (IN over) (NP (CD 100)))))))))
(ROOT (S (VP (VBD ) (PP (IN ) (NP (DT ) (NML (CD ) (HYPH ) (NN )) (JJ ))) (SBAR (WHADVP (WRB )) (S (NP (PRP )) (VP (VBP ) (PP (IN ) (NP (CD )))))))))