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