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