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