I must amuse you must amuse she must amuse we must amuse you must amuse they must amuse
V-ing form
I must be amusing you must be amusing she must be amusing we must be amusing you must be amusing they must be amusing
Perfect
I must have amused you must have amused she 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 she 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 she 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 she 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 she 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 she 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 she amuse? must we amuse? must you amuse? must they amuse?
V-ing form
must I be amusing? must you be amusing? must she be amusing? must we be amusing? must you be amusing? must they be amusing?
Perfect
must I have amused? must you have amused? must she 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 she 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 she 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 she 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 she 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 she have been amusing? mustn't we have been amusing? mustn't you have been amusing? mustn't they have been amusing?