I could blither you could blither he could blither we could blither you could blither they could blither
V-ing form
I could be blithering you could be blithering he could be blithering we could be blithering you could be blithering they could be blithering
Perfect
I could have blithered you could have blithered he could have blithered we could have blithered you could have blithered they could have blithered
V-ing perfect
I could have been blithering you could have been blithering he could have been blithering we could have been blithering you could have been blithering they could have been blithering
Negation
Simple form
I could not blither you could not blither he could not blither we could not blither you could not blither they could not blither
V-ing form
I could not be blithering you could not be blithering he could not be blithering we could not be blithering you could not be blithering they could not be blithering
Perfect
I could not have blithered you could not have blithered he could not have blithered we could not have blithered you could not have blithered they could not have blithered
V-ing perfect
I could not have been blithering you could not have been blithering he could not have been blithering we could not have been blithering you could not have been blithering they could not have been blithering
Interrogative form
Simple form
could I blither? could you blither? could he blither? could we blither? could you blither? could they blither?
V-ing form
could I be blithering? could you be blithering? could he be blithering? could we be blithering? could you be blithering? could they be blithering?
Perfect
could I have blithered? could you have blithered? could he have blithered? could we have blithered? could you have blithered? could they have blithered?
V-ing perfect
could I have been blithering? could you have been blithering? could he have been blithering? could we have been blithering? could you have been blithering? could they have been blithering?
Interro-negative form
Simple form
could I not blither? could you not blither? could he not blither? could we not blither? could you not blither? could they not blither?
V-ing form
could I not be blithering? could you not be blithering? could he not be blithering? could we not be blithering? could you not be blithering? could they not be blithering?
Perfect
could I not have blithered? could you not have blithered? could he not have blithered? could we not have blithered? could you not have blithered? could they not have blithered?
V-ing perfect
could I not have been blithering? could you not have been blithering? could he not have been blithering? could we not have been blithering? could you not have been blithering? could they not have been blithering?