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 couldn't encipher you couldn't encipher he couldn't encipher we couldn't encipher you couldn't encipher they couldn't encipher
V-ing form
I couldn't be enciphering you couldn't be enciphering he couldn't be enciphering we couldn't be enciphering you couldn't be enciphering they couldn't be enciphering
Perfect
I couldn't have enciphered you couldn't have enciphered he couldn't have enciphered we couldn't have enciphered you couldn't have enciphered they couldn't have enciphered
V-ing perfect
I couldn't have been enciphering you couldn't have been enciphering he couldn't have been enciphering we couldn't have been enciphering you couldn't have been enciphering they couldn't 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
couldn't I encipher? couldn't you encipher? couldn't he encipher? couldn't we encipher? couldn't you encipher? couldn't they encipher?
V-ing form
couldn't I be enciphering? couldn't you be enciphering? couldn't he be enciphering? couldn't we be enciphering? couldn't you be enciphering? couldn't they be enciphering?
Perfect
couldn't I have enciphered? couldn't you have enciphered? couldn't he have enciphered? couldn't we have enciphered? couldn't you have enciphered? couldn't they have enciphered?
V-ing perfect
couldn't I have been enciphering? couldn't you have been enciphering? couldn't he have been enciphering? couldn't we have been enciphering? couldn't you have been enciphering? couldn't they have been enciphering?