I must fuck you must fuck he must fuck we must fuck you must fuck they must fuck
V-ing form
I must be fucking you must be fucking he must be fucking we must be fucking you must be fucking they must be fucking
Perfect
I must have fucked you must have fucked he must have fucked we must have fucked you must have fucked they must have fucked
V-ing perfect
I must have been fucking you must have been fucking he must have been fucking we must have been fucking you must have been fucking they must have been fucking
Negation
Simple form
I mustn't fuck you mustn't fuck he mustn't fuck we mustn't fuck you mustn't fuck they mustn't fuck
V-ing form
I mustn't be fucking you mustn't be fucking he mustn't be fucking we mustn't be fucking you mustn't be fucking they mustn't be fucking
Perfect
I mustn't have fucked you mustn't have fucked he mustn't have fucked we mustn't have fucked you mustn't have fucked they mustn't have fucked
V-ing perfect
I mustn't have been fucking you mustn't have been fucking he mustn't have been fucking we mustn't have been fucking you mustn't have been fucking they mustn't have been fucking
Interrogative form
Simple form
must I fuck? must you fuck? must he fuck? must we fuck? must you fuck? must they fuck?
V-ing form
must I be fucking? must you be fucking? must he be fucking? must we be fucking? must you be fucking? must they be fucking?
Perfect
must I have fucked? must you have fucked? must he have fucked? must we have fucked? must you have fucked? must they have fucked?
V-ing perfect
must I have been fucking? must you have been fucking? must he have been fucking? must we have been fucking? must you have been fucking? must they have been fucking?
Interro-negative form
Simple form
mustn't I fuck? mustn't you fuck? mustn't he fuck? mustn't we fuck? mustn't you fuck? mustn't they fuck?
V-ing form
mustn't I be fucking? mustn't you be fucking? mustn't he be fucking? mustn't we be fucking? mustn't you be fucking? mustn't they be fucking?
Perfect
mustn't I have fucked? mustn't you have fucked? mustn't he have fucked? mustn't we have fucked? mustn't you have fucked? mustn't they have fucked?
V-ing perfect
mustn't I have been fucking? mustn't you have been fucking? mustn't he have been fucking? mustn't we have been fucking? mustn't you have been fucking? mustn't they have been fucking?