I could pot you could pot he could pot we could pot you could pot they could pot
V-ing form
I could be potting you could be potting he could be potting we could be potting you could be potting they could be potting
Perfect
I could have potted you could have potted he could have potted we could have potted you could have potted they could have potted
V-ing perfect
I could have been potting you could have been potting he could have been potting we could have been potting you could have been potting they could have been potting
Negation
Simple form
I could not pot you could not pot he could not pot we could not pot you could not pot they could not pot
V-ing form
I could not be potting you could not be potting he could not be potting we could not be potting you could not be potting they could not be potting
Perfect
I could not have potted you could not have potted he could not have potted we could not have potted you could not have potted they could not have potted
V-ing perfect
I could not have been potting you could not have been potting he could not have been potting we could not have been potting you could not have been potting they could not have been potting
Interrogative form
Simple form
could I pot? could you pot? could he pot? could we pot? could you pot? could they pot?
V-ing form
could I be potting? could you be potting? could he be potting? could we be potting? could you be potting? could they be potting?
Perfect
could I have potted? could you have potted? could he have potted? could we have potted? could you have potted? could they have potted?
V-ing perfect
could I have been potting? could you have been potting? could he have been potting? could we have been potting? could you have been potting? could they have been potting?
Interro-negative form
Simple form
could I not pot? could you not pot? could he not pot? could we not pot? could you not pot? could they not pot?
V-ing form
could I not be potting? could you not be potting? could he not be potting? could we not be potting? could you not be potting? could they not be potting?
Perfect
could I not have potted? could you not have potted? could he not have potted? could we not have potted? could you not have potted? could they not have potted?
V-ing perfect
could I not have been potting? could you not have been potting? could he not have been potting? could we not have been potting? could you not have been potting? could they not have been potting?