Boy does skateboard trick.
A boy in a blue shirt is skateboarding.
You can wear anything to skateboard not just a blue shirt.
exists e1 x1 x2.(ne_nam_boy(x1) & Theme(e1,x2) & Actor(e1,x1) & v_skateboard(e1) & n_trick(x2))
exists e1 s1 x1 x2.(Actor(e1,x1) & v_skateboard(e1) & in(x1,x2) & n_shirt(x2) & a_blue(s1) & Theme(s1,x2) & n_boy(x1))