I could pack you could pack he could pack we could pack you could pack they could pack
V-ing form
I could be packing you could be packing he could be packing we could be packing you could be packing they could be packing
Perfect
I could have packed you could have packed he could have packed we could have packed you could have packed they could have packed
V-ing perfect
I could have been packing you could have been packing he could have been packing we could have been packing you could have been packing they could have been packing
Negation
Simple form
I could not pack you could not pack he could not pack we could not pack you could not pack they could not pack
V-ing form
I could not be packing you could not be packing he could not be packing we could not be packing you could not be packing they could not be packing
Perfect
I could not have packed you could not have packed he could not have packed we could not have packed you could not have packed they could not have packed
V-ing perfect
I could not have been packing you could not have been packing he could not have been packing we could not have been packing you could not have been packing they could not have been packing
Interrogative form
Simple form
could I pack? could you pack? could he pack? could we pack? could you pack? could they pack?
V-ing form
could I be packing? could you be packing? could he be packing? could we be packing? could you be packing? could they be packing?
Perfect
could I have packed? could you have packed? could he have packed? could we have packed? could you have packed? could they have packed?
V-ing perfect
could I have been packing? could you have been packing? could he have been packing? could we have been packing? could you have been packing? could they have been packing?
Interro-negative form
Simple form
could I not pack? could you not pack? could he not pack? could we not pack? could you not pack? could they not pack?
V-ing form
could I not be packing? could you not be packing? could he not be packing? could we not be packing? could you not be packing? could they not be packing?
Perfect
could I not have packed? could you not have packed? could he not have packed? could we not have packed? could you not have packed? could they not have packed?
V-ing perfect
could I not have been packing? could you not have been packing? could he not have been packing? could we not have been packing? could you not have been packing? could they not have been packing?