I must fuck you must fuck she must fuck we must fuck you must fuck they must fuck
V-ing form
I must be fucking you must be fucking she must be fucking we must be fucking you must be fucking they must be fucking
Perfect
I must have fucked you must have fucked she 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 she 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 she 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 she 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 she 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 she 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 she fuck? must we fuck? must you fuck? must they fuck?
V-ing form
must I be fucking? must you be fucking? must she be fucking? must we be fucking? must you be fucking? must they be fucking?
Perfect
must I have fucked? must you have fucked? must she 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 she 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 she 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 she 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 she 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 she have been fucking? mustn't we have been fucking? mustn't you have been fucking? mustn't they have been fucking?