I must fluster you must fluster he must fluster we must fluster you must fluster they must fluster
V-ing form
I must be flustering you must be flustering he must be flustering we must be flustering you must be flustering they must be flustering
Perfect
I must have flustered you must have flustered he must have flustered we must have flustered you must have flustered they must have flustered
V-ing perfect
I must have been flustering you must have been flustering he must have been flustering we must have been flustering you must have been flustering they must have been flustering
Negation
Simple form
I mustn't fluster you mustn't fluster he mustn't fluster we mustn't fluster you mustn't fluster they mustn't fluster
V-ing form
I mustn't be flustering you mustn't be flustering he mustn't be flustering we mustn't be flustering you mustn't be flustering they mustn't be flustering
Perfect
I mustn't have flustered you mustn't have flustered he mustn't have flustered we mustn't have flustered you mustn't have flustered they mustn't have flustered
V-ing perfect
I mustn't have been flustering you mustn't have been flustering he mustn't have been flustering we mustn't have been flustering you mustn't have been flustering they mustn't have been flustering
Interrogative form
Simple form
must I fluster? must you fluster? must he fluster? must we fluster? must you fluster? must they fluster?
V-ing form
must I be flustering? must you be flustering? must he be flustering? must we be flustering? must you be flustering? must they be flustering?
Perfect
must I have flustered? must you have flustered? must he have flustered? must we have flustered? must you have flustered? must they have flustered?
V-ing perfect
must I have been flustering? must you have been flustering? must he have been flustering? must we have been flustering? must you have been flustering? must they have been flustering?
Interro-negative form
Simple form
mustn't I fluster? mustn't you fluster? mustn't he fluster? mustn't we fluster? mustn't you fluster? mustn't they fluster?
V-ing form
mustn't I be flustering? mustn't you be flustering? mustn't he be flustering? mustn't we be flustering? mustn't you be flustering? mustn't they be flustering?
Perfect
mustn't I have flustered? mustn't you have flustered? mustn't he have flustered? mustn't we have flustered? mustn't you have flustered? mustn't they have flustered?
V-ing perfect
mustn't I have been flustering? mustn't you have been flustering? mustn't he have been flustering? mustn't we have been flustering? mustn't you have been flustering? mustn't they have been flustering?