I could off you could off he could off we could off you could off they could off
V-ing form
I could be offing you could be offing he could be offing we could be offing you could be offing they could be offing
Perfect
I could have offed you could have offed he could have offed we could have offed you could have offed they could have offed
V-ing perfect
I could have been offing you could have been offing he could have been offing we could have been offing you could have been offing they could have been offing
Negation
Simple form
I could not off you could not off he could not off we could not off you could not off they could not off
V-ing form
I could not be offing you could not be offing he could not be offing we could not be offing you could not be offing they could not be offing
Perfect
I could not have offed you could not have offed he could not have offed we could not have offed you could not have offed they could not have offed
V-ing perfect
I could not have been offing you could not have been offing he could not have been offing we could not have been offing you could not have been offing they could not have been offing
Interrogative form
Simple form
could I off? could you off? could he off? could we off? could you off? could they off?
V-ing form
could I be offing? could you be offing? could he be offing? could we be offing? could you be offing? could they be offing?
Perfect
could I have offed? could you have offed? could he have offed? could we have offed? could you have offed? could they have offed?
V-ing perfect
could I have been offing? could you have been offing? could he have been offing? could we have been offing? could you have been offing? could they have been offing?
Interro-negative form
Simple form
could I not off? could you not off? could he not off? could we not off? could you not off? could they not off?
V-ing form
could I not be offing? could you not be offing? could he not be offing? could we not be offing? could you not be offing? could they not be offing?
Perfect
could I not have offed? could you not have offed? could he not have offed? could we not have offed? could you not have offed? could they not have offed?
V-ing perfect
could I not have been offing? could you not have been offing? could he not have been offing? could we not have been offing? could you not have been offing? could they not have been offing?