if you saw it on tv , you 'd probably turn it off , convinced that you had already seen that movie . 
(ROOT (S (SBAR (IN if) (S (NP (PRP you)) (VP (VBD saw) (NP (PRP it)) (PP (IN on) (NP (NN tv)))))) (, ,) (NP (PRP you)) (VP (MD 'd) (ADVP (RB probably)) (VP (VB turn) (NP (PRP it)) (PRT (RP off)) (, ,) (S (ADJP (VBN convinced) (SBAR (IN that) (S (NP (PRP you)) (VP (VBD had) (ADVP (RB already)) (VP (VBN seen) (NP (DT that) (NN movie)))))))))) (. .)))
(ROOT (S (SBAR (IN ) (S (NP (PRP )) (VP (VBD ) (NP (PRP )) (PP (IN ) (NP (NN )))))) (, ) (NP (PRP )) (VP (MD ) (ADVP (RB )) (VP (VB ) (NP (PRP )) (PRT (RP )) (, ) (S (ADJP (VBN ) (SBAR (IN ) (S (NP (PRP )) (VP (VBD ) (ADVP (RB )) (VP (VBN ) (NP (DT ) (NN )))))))))) (. )))