I could own you could own he could own we could own you could own they could own
V-ing form
I could be owning you could be owning he could be owning we could be owning you could be owning they could be owning
Perfect
I could have owned you could have owned he could have owned we could have owned you could have owned they could have owned
V-ing perfect
I could have been owning you could have been owning he could have been owning we could have been owning you could have been owning they could have been owning
Negation
Simple form
I could not own you could not own he could not own we could not own you could not own they could not own
V-ing form
I could not be owning you could not be owning he could not be owning we could not be owning you could not be owning they could not be owning
Perfect
I could not have owned you could not have owned he could not have owned we could not have owned you could not have owned they could not have owned
V-ing perfect
I could not have been owning you could not have been owning he could not have been owning we could not have been owning you could not have been owning they could not have been owning
Interrogative form
Simple form
could I own? could you own? could he own? could we own? could you own? could they own?
V-ing form
could I be owning? could you be owning? could he be owning? could we be owning? could you be owning? could they be owning?
Perfect
could I have owned? could you have owned? could he have owned? could we have owned? could you have owned? could they have owned?
V-ing perfect
could I have been owning? could you have been owning? could he have been owning? could we have been owning? could you have been owning? could they have been owning?
Interro-negative form
Simple form
could I not own? could you not own? could he not own? could we not own? could you not own? could they not own?
V-ing form
could I not be owning? could you not be owning? could he not be owning? could we not be owning? could you not be owning? could they not be owning?
Perfect
could I not have owned? could you not have owned? could he not have owned? could we not have owned? could you not have owned? could they not have owned?
V-ing perfect
could I not have been owning? could you not have been owning? could he not have been owning? could we not have been owning? could you not have been owning? could they not have been owning?