I could butcher you could butcher he could butcher we could butcher you could butcher they could butcher
V-ing form
I could be butchering you could be butchering he could be butchering we could be butchering you could be butchering they could be butchering
Perfect
I could have butchered you could have butchered he could have butchered we could have butchered you could have butchered they could have butchered
V-ing perfect
I could have been butchering you could have been butchering he could have been butchering we could have been butchering you could have been butchering they could have been butchering
Negation
Simple form
I could not butcher you could not butcher he could not butcher we could not butcher you could not butcher they could not butcher
V-ing form
I could not be butchering you could not be butchering he could not be butchering we could not be butchering you could not be butchering they could not be butchering
Perfect
I could not have butchered you could not have butchered he could not have butchered we could not have butchered you could not have butchered they could not have butchered
V-ing perfect
I could not have been butchering you could not have been butchering he could not have been butchering we could not have been butchering you could not have been butchering they could not have been butchering
Interrogative form
Simple form
could I butcher? could you butcher? could he butcher? could we butcher? could you butcher? could they butcher?
V-ing form
could I be butchering? could you be butchering? could he be butchering? could we be butchering? could you be butchering? could they be butchering?
Perfect
could I have butchered? could you have butchered? could he have butchered? could we have butchered? could you have butchered? could they have butchered?
V-ing perfect
could I have been butchering? could you have been butchering? could he have been butchering? could we have been butchering? could you have been butchering? could they have been butchering?
Interro-negative form
Simple form
could I not butcher? could you not butcher? could he not butcher? could we not butcher? could you not butcher? could they not butcher?
V-ing form
could I not be butchering? could you not be butchering? could he not be butchering? could we not be butchering? could you not be butchering? could they not be butchering?
Perfect
could I not have butchered? could you not have butchered? could he not have butchered? could we not have butchered? could you not have butchered? could they not have butchered?
V-ing perfect
could I not have been butchering? could you not have been butchering? could he not have been butchering? could we not have been butchering? could you not have been butchering? could they not have been butchering?