I could cook you could cook she could cook we could cook you could cook they could cook
V-ing form
I could be cooking you could be cooking she could be cooking we could be cooking you could be cooking they could be cooking
Perfect
I could have cooked you could have cooked she could have cooked we could have cooked you could have cooked they could have cooked
V-ing perfect
I could have been cooking you could have been cooking she could have been cooking we could have been cooking you could have been cooking they could have been cooking
Negation
Simple form
I could not cook you could not cook she could not cook we could not cook you could not cook they could not cook
V-ing form
I could not be cooking you could not be cooking she could not be cooking we could not be cooking you could not be cooking they could not be cooking
Perfect
I could not have cooked you could not have cooked she could not have cooked we could not have cooked you could not have cooked they could not have cooked
V-ing perfect
I could not have been cooking you could not have been cooking she could not have been cooking we could not have been cooking you could not have been cooking they could not have been cooking
Interrogative form
Simple form
could I cook? could you cook? could she cook? could we cook? could you cook? could they cook?
V-ing form
could I be cooking? could you be cooking? could she be cooking? could we be cooking? could you be cooking? could they be cooking?
Perfect
could I have cooked? could you have cooked? could she have cooked? could we have cooked? could you have cooked? could they have cooked?
V-ing perfect
could I have been cooking? could you have been cooking? could she have been cooking? could we have been cooking? could you have been cooking? could they have been cooking?
Interro-negative form
Simple form
could I not cook? could you not cook? could she not cook? could we not cook? could you not cook? could they not cook?
V-ing form
could I not be cooking? could you not be cooking? could she not be cooking? could we not be cooking? could you not be cooking? could they not be cooking?
Perfect
could I not have cooked? could you not have cooked? could she not have cooked? could we not have cooked? could you not have cooked? could they not have cooked?
V-ing perfect
could I not have been cooking? could you not have been cooking? could she not have been cooking? could we not have been cooking? could you not have been cooking? could they not have been cooking?