I must stay you must stay she must stay we must stay you must stay they must stay
V-ing form
I must be staying you must be staying she must be staying we must be staying you must be staying they must be staying
Perfect
I must have stayed you must have stayed she must have stayed we must have stayed you must have stayed they must have stayed
V-ing perfect
I must have been staying you must have been staying she must have been staying we must have been staying you must have been staying they must have been staying
Negation
Simple form
I must not stay you must not stay she must not stay we must not stay you must not stay they must not stay
V-ing form
I must not be staying you must not be staying she must not be staying we must not be staying you must not be staying they must not be staying
Perfect
I must not have stayed you must not have stayed she must not have stayed we must not have stayed you must not have stayed they must not have stayed
V-ing perfect
I must not have been staying you must not have been staying she must not have been staying we must not have been staying you must not have been staying they must not have been staying
Interrogative form
Simple form
must I stay? must you stay? must she stay? must we stay? must you stay? must they stay?
V-ing form
must I be staying? must you be staying? must she be staying? must we be staying? must you be staying? must they be staying?
Perfect
must I have stayed? must you have stayed? must she have stayed? must we have stayed? must you have stayed? must they have stayed?
V-ing perfect
must I have been staying? must you have been staying? must she have been staying? must we have been staying? must you have been staying? must they have been staying?
Interro-negative form
Simple form
must I not stay? must you not stay? must she not stay? must we not stay? must you not stay? must they not stay?
V-ing form
must I not be staying? must you not be staying? must she not be staying? must we not be staying? must you not be staying? must they not be staying?
Perfect
must I not have stayed? must you not have stayed? must she not have stayed? must we not have stayed? must you not have stayed? must they not have stayed?
V-ing perfect
must I not have been staying? must you not have been staying? must she not have been staying? must we not have been staying? must you not have been staying? must they not have been staying?