A man is leaning on a skateboard while holding onto a pole.
a man knows how to ride a skateboard
learning  doesn't always mean knows
exists e2 e1 x1 x2 x3.(while(e1,e2) & onto(e2,x3) & n_pole(x3) & Actor(e2,x1) & v_hold(e2) & on(e1,x2) & n_skateboard(x2) & Actor(e1,x1) & v_lean(e1) & n_man(x1))
exists e1 x1 x2.(Topic(e1,x2) & Actor(e1,x1) & v_know(e1) & n_manner(x2) & exists e2 x3 x4.(Theme(e2,x4) & Actor(e2,x3) & v_ride(e2) & n_skateboard(x4)) & n_man(x1))