You don't know.
( You ( ( ( do n't ) know ) . ) )
(ROOT (S (NP (PRP You)) (VP (VBP do) (RB n't) (VP (VB know))) (. .)))
You don't know if he loves you.
( You ( ( ( do n't ) ( know ( if ( he ( loves you ) ) ) ) ) . ) )
(ROOT (S (NP (PRP You)) (VP (VBP do) (RB n't) (VP (VB know) (SBAR (IN if) (S (NP (PRP he)) (VP (VBZ loves) (NP (PRP you))))))) (. .)))