I must sleep you must sleep she must sleep we must sleep you must sleep they must sleep
V-ing form
I must be sleeping you must be sleeping she must be sleeping we must be sleeping you must be sleeping they must be sleeping
Perfect
I must have slept you must have slept she must have slept we must have slept you must have slept they must have slept
V-ing perfect
I must have been sleeping you must have been sleeping she must have been sleeping we must have been sleeping you must have been sleeping they must have been sleeping
Negation
Simple form
I mustn't sleep you mustn't sleep she mustn't sleep we mustn't sleep you mustn't sleep they mustn't sleep
V-ing form
I mustn't be sleeping you mustn't be sleeping she mustn't be sleeping we mustn't be sleeping you mustn't be sleeping they mustn't be sleeping
Perfect
I mustn't have slept you mustn't have slept she mustn't have slept we mustn't have slept you mustn't have slept they mustn't have slept
V-ing perfect
I mustn't have been sleeping you mustn't have been sleeping she mustn't have been sleeping we mustn't have been sleeping you mustn't have been sleeping they mustn't have been sleeping
Interrogative form
Simple form
must I sleep? must you sleep? must she sleep? must we sleep? must you sleep? must they sleep?
V-ing form
must I be sleeping? must you be sleeping? must she be sleeping? must we be sleeping? must you be sleeping? must they be sleeping?
Perfect
must I have slept? must you have slept? must she have slept? must we have slept? must you have slept? must they have slept?
V-ing perfect
must I have been sleeping? must you have been sleeping? must she have been sleeping? must we have been sleeping? must you have been sleeping? must they have been sleeping?
Interro-negative form
Simple form
mustn't I sleep? mustn't you sleep? mustn't she sleep? mustn't we sleep? mustn't you sleep? mustn't they sleep?
V-ing form
mustn't I be sleeping? mustn't you be sleeping? mustn't she be sleeping? mustn't we be sleeping? mustn't you be sleeping? mustn't they be sleeping?
Perfect
mustn't I have slept? mustn't you have slept? mustn't she have slept? mustn't we have slept? mustn't you have slept? mustn't they have slept?
V-ing perfect
mustn't I have been sleeping? mustn't you have been sleeping? mustn't she have been sleeping? mustn't we have been sleeping? mustn't you have been sleeping? mustn't they have been sleeping?