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