My mom knows.
( ( My mom ) ( knows . ) )
(ROOT (S (NP (PRP$ My) (NN mom)) (VP (VBZ knows)) (. .)))
My mother does not know about this.
( ( My mother ) ( ( ( does not ) ( know ( about this ) ) ) . ) )
(ROOT (S (NP (PRP$ My) (NN mother)) (VP (VBZ does) (RB not) (VP (VB know) (PP (IN about) (NP (DT this))))) (. .)))