I must sleep you must sleep he must sleep we must sleep you must sleep they must sleep
V-ing form
I must be sleeping you must be sleeping he must be sleeping we must be sleeping you must be sleeping they must be sleeping
Perfect
I must have slept you must have slept he 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 he 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 he 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 he 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 he 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 he 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 he sleep? must we sleep? must you sleep? must they sleep?
V-ing form
must I be sleeping? must you be sleeping? must he be sleeping? must we be sleeping? must you be sleeping? must they be sleeping?
Perfect
must I have slept? must you have slept? must he 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 he 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 he 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 he 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 he 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 he have been sleeping? mustn't we have been sleeping? mustn't you have been sleeping? mustn't they have been sleeping?