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