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