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