I must shake you must shake she must shake we must shake you must shake they must shake
V-ing form
I must be shaking you must be shaking she must be shaking we must be shaking you must be shaking they must be shaking
Perfect
I must have shaken you must have shaken she 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 she 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 she 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 she 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 she 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 she 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 she shake? must we shake? must you shake? must they shake?
V-ing form
must I be shaking? must you be shaking? must she be shaking? must we be shaking? must you be shaking? must they be shaking?
Perfect
must I have shaken? must you have shaken? must she 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 she 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 she 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 she 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 she 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 she have been shaking? mustn't we have been shaking? mustn't you have been shaking? mustn't they have been shaking?