I could encipher you could encipher he could encipher we could encipher you could encipher they could encipher
V-ing form
I could be enciphering you could be enciphering he could be enciphering we could be enciphering you could be enciphering they could be enciphering
Perfect
I could have enciphered you could have enciphered he could have enciphered we could have enciphered you could have enciphered they could have enciphered
V-ing perfect
I could have been enciphering you could have been enciphering he could have been enciphering we could have been enciphering you could have been enciphering they could have been enciphering
Negation
Simple form
I could not encipher you could not encipher he could not encipher we could not encipher you could not encipher they could not encipher
V-ing form
I could not be enciphering you could not be enciphering he could not be enciphering we could not be enciphering you could not be enciphering they could not be enciphering
Perfect
I could not have enciphered you could not have enciphered he could not have enciphered we could not have enciphered you could not have enciphered they could not have enciphered
V-ing perfect
I could not have been enciphering you could not have been enciphering he could not have been enciphering we could not have been enciphering you could not have been enciphering they could not have been enciphering
Interrogative form
Simple form
could I encipher? could you encipher? could he encipher? could we encipher? could you encipher? could they encipher?
V-ing form
could I be enciphering? could you be enciphering? could he be enciphering? could we be enciphering? could you be enciphering? could they be enciphering?
Perfect
could I have enciphered? could you have enciphered? could he have enciphered? could we have enciphered? could you have enciphered? could they have enciphered?
V-ing perfect
could I have been enciphering? could you have been enciphering? could he have been enciphering? could we have been enciphering? could you have been enciphering? could they have been enciphering?
Interro-negative form
Simple form
could I not encipher? could you not encipher? could he not encipher? could we not encipher? could you not encipher? could they not encipher?
V-ing form
could I not be enciphering? could you not be enciphering? could he not be enciphering? could we not be enciphering? could you not be enciphering? could they not be enciphering?
Perfect
could I not have enciphered? could you not have enciphered? could he not have enciphered? could we not have enciphered? could you not have enciphered? could they not have enciphered?
V-ing perfect
could I not have been enciphering? could you not have been enciphering? could he not have been enciphering? could we not have been enciphering? could you not have been enciphering? could they not have been enciphering?