I could possess you could possess he could possess we could possess you could possess they could possess
V-ing form
I could be possessing you could be possessing he could be possessing we could be possessing you could be possessing they could be possessing
Perfect
I could have possessed you could have possessed he could have possessed we could have possessed you could have possessed they could have possessed
V-ing perfect
I could have been possessing you could have been possessing he could have been possessing we could have been possessing you could have been possessing they could have been possessing
Negation
Simple form
I could not possess you could not possess he could not possess we could not possess you could not possess they could not possess
V-ing form
I could not be possessing you could not be possessing he could not be possessing we could not be possessing you could not be possessing they could not be possessing
Perfect
I could not have possessed you could not have possessed he could not have possessed we could not have possessed you could not have possessed they could not have possessed
V-ing perfect
I could not have been possessing you could not have been possessing he could not have been possessing we could not have been possessing you could not have been possessing they could not have been possessing
Interrogative form
Simple form
could I possess? could you possess? could he possess? could we possess? could you possess? could they possess?
V-ing form
could I be possessing? could you be possessing? could he be possessing? could we be possessing? could you be possessing? could they be possessing?
Perfect
could I have possessed? could you have possessed? could he have possessed? could we have possessed? could you have possessed? could they have possessed?
V-ing perfect
could I have been possessing? could you have been possessing? could he have been possessing? could we have been possessing? could you have been possessing? could they have been possessing?
Interro-negative form
Simple form
could I not possess? could you not possess? could he not possess? could we not possess? could you not possess? could they not possess?
V-ing form
could I not be possessing? could you not be possessing? could he not be possessing? could we not be possessing? could you not be possessing? could they not be possessing?
Perfect
could I not have possessed? could you not have possessed? could he not have possessed? could we not have possessed? could you not have possessed? could they not have possessed?
V-ing perfect
could I not have been possessing? could you not have been possessing? could he not have been possessing? could we not have been possessing? could you not have been possessing? could they not have been possessing?