Some kids play in a field.
Some children play in a field.
Children are kids and both sentences mentions them playing in a field.
exists e1 x1 x2.(in(e1,x2) & n_field(x2) & Actor(e1,x1) & v_play(e1) & n_kid(x1))
exists e1 x1 x2.(in(e1,x2) & n_field(x2) & Actor(e1,x1) & v_play(e1) & n_child(x1))