I must decipher you must decipher she must decipher we must decipher you must decipher they must decipher
V-ing form
I must be deciphering you must be deciphering she must be deciphering we must be deciphering you must be deciphering they must be deciphering
Perfect
I must have deciphered you must have deciphered she must have deciphered we must have deciphered you must have deciphered they must have deciphered
V-ing perfect
I must have been deciphering you must have been deciphering she must have been deciphering we must have been deciphering you must have been deciphering they must have been deciphering
Negation
Simple form
I must not decipher you must not decipher she must not decipher we must not decipher you must not decipher they must not decipher
V-ing form
I must not be deciphering you must not be deciphering she must not be deciphering we must not be deciphering you must not be deciphering they must not be deciphering
Perfect
I must not have deciphered you must not have deciphered she must not have deciphered we must not have deciphered you must not have deciphered they must not have deciphered
V-ing perfect
I must not have been deciphering you must not have been deciphering she must not have been deciphering we must not have been deciphering you must not have been deciphering they must not have been deciphering
Interrogative form
Simple form
must I decipher? must you decipher? must she decipher? must we decipher? must you decipher? must they decipher?
V-ing form
must I be deciphering? must you be deciphering? must she be deciphering? must we be deciphering? must you be deciphering? must they be deciphering?
Perfect
must I have deciphered? must you have deciphered? must she have deciphered? must we have deciphered? must you have deciphered? must they have deciphered?
V-ing perfect
must I have been deciphering? must you have been deciphering? must she have been deciphering? must we have been deciphering? must you have been deciphering? must they have been deciphering?
Interro-negative form
Simple form
must I not decipher? must you not decipher? must she not decipher? must we not decipher? must you not decipher? must they not decipher?
V-ing form
must I not be deciphering? must you not be deciphering? must she not be deciphering? must we not be deciphering? must you not be deciphering? must they not be deciphering?
Perfect
must I not have deciphered? must you not have deciphered? must she not have deciphered? must we not have deciphered? must you not have deciphered? must they not have deciphered?
V-ing perfect
must I not have been deciphering? must you not have been deciphering? must she not have been deciphering? must we not have been deciphering? must you not have been deciphering? must they not have been deciphering?