A man in a red and white shirt is sitting on a motorcycle.
A man in a red and white shirt is preparing to ride a motorcycle.
Just because a man is sitting on a motorcycle it doesn't mean he is preparing to ride it. He may just be sitting on it to rest.
exists e1 s1 s2 x1 x2 x3.(on(e1,x3) & n_motorcycle(x3) & Actor(e1,x1) & v_sit(e1) & in(x1,x2) & n_shirt(x2) & a_white(s2) & Theme(s2,x2) & a_red(s1) & Theme(s1,x2) & n_man(x1))
exists e1 p1 s1 s2 x1 x2.(Topic(e1,p1) & Actor(e1,x1) & v_prepare(e1) & exists e2 x3.(Theme(e2,x3) & Actor(e2,x1) & v_ride(e2) & n_motorcycle(x3)) & in(x1,x2) & n_shirt(x2) & a_white(s2) & Theme(s2,x2) & a_red(s1) & Theme(s1,x2) & n_man(x1))