I could dicker you could dicker he could dicker we could dicker you could dicker they could dicker
V-ing form
I could be dickering you could be dickering he could be dickering we could be dickering you could be dickering they could be dickering
Perfect
I could have dickered you could have dickered he could have dickered we could have dickered you could have dickered they could have dickered
V-ing perfect
I could have been dickering you could have been dickering he could have been dickering we could have been dickering you could have been dickering they could have been dickering
Negation
Simple form
I could not dicker you could not dicker he could not dicker we could not dicker you could not dicker they could not dicker
V-ing form
I could not be dickering you could not be dickering he could not be dickering we could not be dickering you could not be dickering they could not be dickering
Perfect
I could not have dickered you could not have dickered he could not have dickered we could not have dickered you could not have dickered they could not have dickered
V-ing perfect
I could not have been dickering you could not have been dickering he could not have been dickering we could not have been dickering you could not have been dickering they could not have been dickering
Interrogative form
Simple form
could I dicker? could you dicker? could he dicker? could we dicker? could you dicker? could they dicker?
V-ing form
could I be dickering? could you be dickering? could he be dickering? could we be dickering? could you be dickering? could they be dickering?
Perfect
could I have dickered? could you have dickered? could he have dickered? could we have dickered? could you have dickered? could they have dickered?
V-ing perfect
could I have been dickering? could you have been dickering? could he have been dickering? could we have been dickering? could you have been dickering? could they have been dickering?
Interro-negative form
Simple form
could I not dicker? could you not dicker? could he not dicker? could we not dicker? could you not dicker? could they not dicker?
V-ing form
could I not be dickering? could you not be dickering? could he not be dickering? could we not be dickering? could you not be dickering? could they not be dickering?
Perfect
could I not have dickered? could you not have dickered? could he not have dickered? could we not have dickered? could you not have dickered? could they not have dickered?
V-ing perfect
could I not have been dickering? could you not have been dickering? could he not have been dickering? could we not have been dickering? could you not have been dickering? could they not have been dickering?