A man with a black shirt watching a baby.
A man watches over his son.
Just because a man is with a baby it doesn't mean the baby is his son.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & with(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_watch(e1) & n_baby(x4) & (x2 = x3) & n_shirt(x2) & a_black(s1) & Theme(s1,x2) & n_man(x1))
exists e1 x1 x2.(over(e1,x2) & n_son(x2) & of(x2,x1) & n_male(x1) & Actor(e1,x1) & v_watch(e1) & n_man(x1))