I could shop you could shop she could shop we could shop you could shop they could shop
V-ing form
I could be shopping you could be shopping she could be shopping we could be shopping you could be shopping they could be shopping
Perfect
I could have shopped you could have shopped she could have shopped we could have shopped you could have shopped they could have shopped
V-ing perfect
I could have been shopping you could have been shopping she could have been shopping we could have been shopping you could have been shopping they could have been shopping
Negation
Simple form
I could not shop you could not shop she could not shop we could not shop you could not shop they could not shop
V-ing form
I could not be shopping you could not be shopping she could not be shopping we could not be shopping you could not be shopping they could not be shopping
Perfect
I could not have shopped you could not have shopped she could not have shopped we could not have shopped you could not have shopped they could not have shopped
V-ing perfect
I could not have been shopping you could not have been shopping she could not have been shopping we could not have been shopping you could not have been shopping they could not have been shopping
Interrogative form
Simple form
could I shop? could you shop? could she shop? could we shop? could you shop? could they shop?
V-ing form
could I be shopping? could you be shopping? could she be shopping? could we be shopping? could you be shopping? could they be shopping?
Perfect
could I have shopped? could you have shopped? could she have shopped? could we have shopped? could you have shopped? could they have shopped?
V-ing perfect
could I have been shopping? could you have been shopping? could she have been shopping? could we have been shopping? could you have been shopping? could they have been shopping?
Interro-negative form
Simple form
could I not shop? could you not shop? could she not shop? could we not shop? could you not shop? could they not shop?
V-ing form
could I not be shopping? could you not be shopping? could she not be shopping? could we not be shopping? could you not be shopping? could they not be shopping?
Perfect
could I not have shopped? could you not have shopped? could she not have shopped? could we not have shopped? could you not have shopped? could they not have shopped?
V-ing perfect
could I not have been shopping? could you not have been shopping? could she not have been shopping? could we not have been shopping? could you not have been shopping? could they not have been shopping?