My cousin's.
( ( My cousin ) ( 's . ) )
(ROOT (S (NP (PRP$ My) (NN cousin)) (VP (VBZ 's)) (. .)))
That does not belong to my cousin.
( That ( ( ( does not ) ( belong ( to ( my cousin ) ) ) ) . ) )
(ROOT (S (NP (DT That)) (VP (VBZ does) (RB not) (VP (VB belong) (PP (TO to) (NP (PRP$ my) (NN cousin))))) (. .)))