I could film you could film he could film we could film you could film they could film
V-ing form
I could be filming you could be filming he could be filming we could be filming you could be filming they could be filming
Perfect
I could have filmed you could have filmed he 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 he could have been filming we could have been filming you could have been filming they could have been filming
Negation
Simple form
I couldn't film you couldn't film he couldn't film we couldn't film you couldn't film they couldn't film
V-ing form
I couldn't be filming you couldn't be filming he couldn't be filming we couldn't be filming you couldn't be filming they couldn't be filming
Perfect
I couldn't have filmed you couldn't have filmed he couldn't have filmed we couldn't have filmed you couldn't have filmed they couldn't have filmed
V-ing perfect
I couldn't have been filming you couldn't have been filming he couldn't have been filming we couldn't have been filming you couldn't have been filming they couldn't have been filming
Interrogative form
Simple form
could I film? could you film? could he film? could we film? could you film? could they film?
V-ing form
could I be filming? could you be filming? could he be filming? could we be filming? could you be filming? could they be filming?
Perfect
could I have filmed? could you have filmed? could he 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 he have been filming? could we have been filming? could you have been filming? could they have been filming?
Interro-negative form
Simple form
couldn't I film? couldn't you film? couldn't he film? couldn't we film? couldn't you film? couldn't they film?
V-ing form
couldn't I be filming? couldn't you be filming? couldn't he be filming? couldn't we be filming? couldn't you be filming? couldn't they be filming?
Perfect
couldn't I have filmed? couldn't you have filmed? couldn't he have filmed? couldn't we have filmed? couldn't you have filmed? couldn't they have filmed?
V-ing perfect
couldn't I have been filming? couldn't you have been filming? couldn't he have been filming? couldn't we have been filming? couldn't you have been filming? couldn't they have been filming?