must perdure
Regular verb: perdure - perdured- perdured

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must perdure
you must perdure
he must perdure
we must perdure
you must perdure
they must perdure 	I must be perduring
you must be perduring
he must be perduring
we must be perduring
you must be perduring
they must be perduring	I must have perdured
you must have perdured
he must have perdured
we must have perdured
you must have perdured
they must have perdured	I must have been perduring
you must have been perduring
he must have been perduring
we must have been perduring
you must have been perduring
they must have been perduring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't perdure
you mustn't perdure
he mustn't perdure
we mustn't perdure
you mustn't perdure
they mustn't perdure 	I mustn't be perduring
you mustn't be perduring
he mustn't be perduring
we mustn't be perduring
you mustn't be perduring
they mustn't be perduring	I mustn't have perdured
you mustn't have perdured
he mustn't have perdured
we mustn't have perdured
you mustn't have perdured
they mustn't have perdured	I mustn't have been perduring
you mustn't have been perduring
he mustn't have been perduring
we mustn't have been perduring
you mustn't have been perduring
they mustn't have been perduring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I perdure?
must you perdure?
must he perdure?
must we perdure?
must you perdure?
must they perdure? 	must I be perduring?
must you be perduring?
must he be perduring?
must we be perduring?
must you be perduring?
must they be perduring? 	must I have perdured?
must you have perdured?
must he have perdured?
must we have perdured?
must you have perdured?
must they have perdured? 	must I have been perduring?
must you have been perduring?
must he have been perduring?
must we have been perduring?
must you have been perduring?
must they have been perduring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I perdure?
mustn't you perdure?
mustn't he perdure?
mustn't we perdure?
mustn't you perdure?
mustn't they perdure? 	mustn't I be perduring?
mustn't you be perduring?
mustn't he be perduring?
mustn't we be perduring?
mustn't you be perduring?
mustn't they be perduring? 	mustn't I have perdured?
mustn't you have perdured?
mustn't he have perdured?
mustn't we have perdured?
mustn't you have perdured?
mustn't they have perdured? 	mustn't I have been perduring?
mustn't you have been perduring?
mustn't he have been perduring?
mustn't we have been perduring?
mustn't you have been perduring?
mustn't they have been perduring?