I could cackle you could cackle he could cackle we could cackle you could cackle they could cackle
V-ing form
I could be cackling you could be cackling he could be cackling we could be cackling you could be cackling they could be cackling
Perfect
I could have cackled you could have cackled he 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 he 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 he 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 he 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 he 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 he 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 he cackle? could we cackle? could you cackle? could they cackle?
V-ing form
could I be cackling? could you be cackling? could he be cackling? could we be cackling? could you be cackling? could they be cackling?
Perfect
could I have cackled? could you have cackled? could he 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 he 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 he 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 he 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 he 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 he not have been cackling? could we not have been cackling? could you not have been cackling? could they not have been cackling?