I could canal you could canal he could canal we could canal you could canal they could canal
V-ing form
I could be canaling you could be canaling he could be canaling we could be canaling you could be canaling they could be canaling
Perfect
I could have canaled you could have canaled he could have canaled we could have canaled you could have canaled they could have canaled
V-ing perfect
I could have been canaling you could have been canaling he could have been canaling we could have been canaling you could have been canaling they could have been canaling
Negation
Simple form
I could not canal you could not canal he could not canal we could not canal you could not canal they could not canal
V-ing form
I could not be canaling you could not be canaling he could not be canaling we could not be canaling you could not be canaling they could not be canaling
Perfect
I could not have canaled you could not have canaled he could not have canaled we could not have canaled you could not have canaled they could not have canaled
V-ing perfect
I could not have been canaling you could not have been canaling he could not have been canaling we could not have been canaling you could not have been canaling they could not have been canaling
Interrogative form
Simple form
could I canal? could you canal? could he canal? could we canal? could you canal? could they canal?
V-ing form
could I be canaling? could you be canaling? could he be canaling? could we be canaling? could you be canaling? could they be canaling?
Perfect
could I have canaled? could you have canaled? could he have canaled? could we have canaled? could you have canaled? could they have canaled?
V-ing perfect
could I have been canaling? could you have been canaling? could he have been canaling? could we have been canaling? could you have been canaling? could they have been canaling?
Interro-negative form
Simple form
could I not canal? could you not canal? could he not canal? could we not canal? could you not canal? could they not canal?
V-ing form
could I not be canaling? could you not be canaling? could he not be canaling? could we not be canaling? could you not be canaling? could they not be canaling?
Perfect
could I not have canaled? could you not have canaled? could he not have canaled? could we not have canaled? could you not have canaled? could they not have canaled?
V-ing perfect
could I not have been canaling? could you not have been canaling? could he not have been canaling? could we not have been canaling? could you not have been canaling? could they not have been canaling?