must withstand
Irregular verb: withstand - withstood- withstood

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must withstand
you must withstand
he must withstand
we must withstand
you must withstand
they must withstand 	I must be withstanding
you must be withstanding
he must be withstanding
we must be withstanding
you must be withstanding
they must be withstanding	I must have withstood
you must have withstood
he must have withstood
we must have withstood
you must have withstood
they must have withstood	I must have been withstanding
you must have been withstanding
he must have been withstanding
we must have been withstanding
you must have been withstanding
they must have been withstanding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't withstand
you mustn't withstand
he mustn't withstand
we mustn't withstand
you mustn't withstand
they mustn't withstand 	I mustn't be withstanding
you mustn't be withstanding
he mustn't be withstanding
we mustn't be withstanding
you mustn't be withstanding
they mustn't be withstanding	I mustn't have withstood
you mustn't have withstood
he mustn't have withstood
we mustn't have withstood
you mustn't have withstood
they mustn't have withstood	I mustn't have been withstanding
you mustn't have been withstanding
he mustn't have been withstanding
we mustn't have been withstanding
you mustn't have been withstanding
they mustn't have been withstanding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I withstand?
must you withstand?
must he withstand?
must we withstand?
must you withstand?
must they withstand? 	must I be withstanding?
must you be withstanding?
must he be withstanding?
must we be withstanding?
must you be withstanding?
must they be withstanding? 	must I have withstood?
must you have withstood?
must he have withstood?
must we have withstood?
must you have withstood?
must they have withstood? 	must I have been withstanding?
must you have been withstanding?
must he have been withstanding?
must we have been withstanding?
must you have been withstanding?
must they have been withstanding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I withstand?
mustn't you withstand?
mustn't he withstand?
mustn't we withstand?
mustn't you withstand?
mustn't they withstand? 	mustn't I be withstanding?
mustn't you be withstanding?
mustn't he be withstanding?
mustn't we be withstanding?
mustn't you be withstanding?
mustn't they be withstanding? 	mustn't I have withstood?
mustn't you have withstood?
mustn't he have withstood?
mustn't we have withstood?
mustn't you have withstood?
mustn't they have withstood? 	mustn't I have been withstanding?
mustn't you have been withstanding?
mustn't he have been withstanding?
mustn't we have been withstanding?
mustn't you have been withstanding?
mustn't they have been withstanding?