I could cackle you could cackle she could cackle we could cackle you could cackle they could cackle
V-ing form
I could be cackling you could be cackling she could be cackling we could be cackling you could be cackling they could be cackling
Perfect
I could have cackled you could have cackled she could have cackled we could have cackled you could have cackled they could have cackled
V-ing perfect
I could have been cackling you could have been cackling she could have been cackling we could have been cackling you could have been cackling they could have been cackling
Negation
Simple form
I could not cackle you could not cackle she could not cackle we could not cackle you could not cackle they could not cackle
V-ing form
I could not be cackling you could not be cackling she could not be cackling we could not be cackling you could not be cackling they could not be cackling
Perfect
I could not have cackled you could not have cackled she could not have cackled we could not have cackled you could not have cackled they could not have cackled
V-ing perfect
I could not have been cackling you could not have been cackling she could not have been cackling we could not have been cackling you could not have been cackling they could not have been cackling
Interrogative form
Simple form
could I cackle? could you cackle? could she cackle? could we cackle? could you cackle? could they cackle?
V-ing form
could I be cackling? could you be cackling? could she be cackling? could we be cackling? could you be cackling? could they be cackling?
Perfect
could I have cackled? could you have cackled? could she have cackled? could we have cackled? could you have cackled? could they have cackled?
V-ing perfect
could I have been cackling? could you have been cackling? could she have been cackling? could we have been cackling? could you have been cackling? could they have been cackling?
Interro-negative form
Simple form
could I not cackle? could you not cackle? could she not cackle? could we not cackle? could you not cackle? could they not cackle?
V-ing form
could I not be cackling? could you not be cackling? could she not be cackling? could we not be cackling? could you not be cackling? could they not be cackling?
Perfect
could I not have cackled? could you not have cackled? could she not have cackled? could we not have cackled? could you not have cackled? could they not have cackled?
V-ing perfect
could I not have been cackling? could you not have been cackling? could she not have been cackling? could we not have been cackling? could you not have been cackling? could they not have been cackling?