I must flit you must flit he must flit we must flit you must flit they must flit
V-ing form
I must be flitting you must be flitting he must be flitting we must be flitting you must be flitting they must be flitting
Perfect
I must have flitted you must have flitted he 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 he 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 he 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 he 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 he 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 he 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 he flit? must we flit? must you flit? must they flit?
V-ing form
must I be flitting? must you be flitting? must he be flitting? must we be flitting? must you be flitting? must they be flitting?
Perfect
must I have flitted? must you have flitted? must he 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 he 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 he 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 he 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 he 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 he have been flitting? mustn't we have been flitting? mustn't you have been flitting? mustn't they have been flitting?