I could chopper you could chopper she could chopper we could chopper you could chopper they could chopper
V-ing form
I could be choppering you could be choppering she could be choppering we could be choppering you could be choppering they could be choppering
Perfect
I could have choppered you could have choppered she could have choppered we could have choppered you could have choppered they could have choppered
V-ing perfect
I could have been choppering you could have been choppering she could have been choppering we could have been choppering you could have been choppering they could have been choppering
Negation
Simple form
I could not chopper you could not chopper she could not chopper we could not chopper you could not chopper they could not chopper
V-ing form
I could not be choppering you could not be choppering she could not be choppering we could not be choppering you could not be choppering they could not be choppering
Perfect
I could not have choppered you could not have choppered she could not have choppered we could not have choppered you could not have choppered they could not have choppered
V-ing perfect
I could not have been choppering you could not have been choppering she could not have been choppering we could not have been choppering you could not have been choppering they could not have been choppering
Interrogative form
Simple form
could I chopper? could you chopper? could she chopper? could we chopper? could you chopper? could they chopper?
V-ing form
could I be choppering? could you be choppering? could she be choppering? could we be choppering? could you be choppering? could they be choppering?
Perfect
could I have choppered? could you have choppered? could she have choppered? could we have choppered? could you have choppered? could they have choppered?
V-ing perfect
could I have been choppering? could you have been choppering? could she have been choppering? could we have been choppering? could you have been choppering? could they have been choppering?
Interro-negative form
Simple form
could I not chopper? could you not chopper? could she not chopper? could we not chopper? could you not chopper? could they not chopper?
V-ing form
could I not be choppering? could you not be choppering? could she not be choppering? could we not be choppering? could you not be choppering? could they not be choppering?
Perfect
could I not have choppered? could you not have choppered? could she not have choppered? could we not have choppered? could you not have choppered? could they not have choppered?
V-ing perfect
could I not have been choppering? could you not have been choppering? could she not have been choppering? could we not have been choppering? could you not have been choppering? could they not have been choppering?