Young boy in blue jacket learns to ride a skateboard.
A human in a jacket.
the human is an young boy and he is in jacket shows that he wears blue jacket
exists p1 s1 s2 x1 x2 x3.(a_topic(x1) & in(x1,x2) & Topic(x2,p1) & exists e1 x4.(Theme(e1,x4) & Actor(e1,x2) & v_ride(e1) & n_skateboard(x4)) & n_learn(x2) & of(x2,x3) & n_jacket(x3) & a_blue(s2) & Theme(s2,x2) & n_boy(x1) & a_young(s1) & Theme(s1,x1))
exists x1 x2.(a_topic(x1) & in(x1,x2) & n_jacket(x2) & n_human(x1))