The sky appears clear.
The sky looked very clear at night.
The sky can appear clear both in the day and at night.
exists e1 p1 x1.(n_sky(x1) & exists s1.(Theme(s1,x1) & a_clear(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_appear(e1))
exists e1 p1 x1 x2.(n_sky(x1) & at(e1,x2) & n_night(x2) & exists s1.(r_very(s1) & Theme(s1,x1) & a_clear(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_look(e1))