I could film you could film she could film we could film you could film they could film
V-ing form
I could be filming you could be filming she could be filming we could be filming you could be filming they could be filming
Perfect
I could have filmed you could have filmed she could have filmed we could have filmed you could have filmed they could have filmed
V-ing perfect
I could have been filming you could have been filming she could have been filming we could have been filming you could have been filming they could have been filming
Negation
Simple form
I could not film you could not film she could not film we could not film you could not film they could not film
V-ing form
I could not be filming you could not be filming she could not be filming we could not be filming you could not be filming they could not be filming
Perfect
I could not have filmed you could not have filmed she could not have filmed we could not have filmed you could not have filmed they could not have filmed
V-ing perfect
I could not have been filming you could not have been filming she could not have been filming we could not have been filming you could not have been filming they could not have been filming
Interrogative form
Simple form
could I film? could you film? could she film? could we film? could you film? could they film?
V-ing form
could I be filming? could you be filming? could she be filming? could we be filming? could you be filming? could they be filming?
Perfect
could I have filmed? could you have filmed? could she have filmed? could we have filmed? could you have filmed? could they have filmed?
V-ing perfect
could I have been filming? could you have been filming? could she have been filming? could we have been filming? could you have been filming? could they have been filming?
Interro-negative form
Simple form
could I not film? could you not film? could she not film? could we not film? could you not film? could they not film?
V-ing form
could I not be filming? could you not be filming? could she not be filming? could we not be filming? could you not be filming? could they not be filming?
Perfect
could I not have filmed? could you not have filmed? could she not have filmed? could we not have filmed? could you not have filmed? could they not have filmed?
V-ing perfect
could I not have been filming? could you not have been filming? could she not have been filming? could we not have been filming? could you not have been filming? could they not have been filming?