must undergo
Irregular verb: undergo - underwent- undergone

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must undergo
you must undergo
she must undergo
we must undergo
you must undergo
they must undergo 	I must be undergoing
you must be undergoing
she must be undergoing
we must be undergoing
you must be undergoing
they must be undergoing	I must have undergone
you must have undergone
she must have undergone
we must have undergone
you must have undergone
they must have undergone	I must have been undergoing
you must have been undergoing
she must have been undergoing
we must have been undergoing
you must have been undergoing
they must have been undergoing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't undergo
you mustn't undergo
she mustn't undergo
we mustn't undergo
you mustn't undergo
they mustn't undergo 	I mustn't be undergoing
you mustn't be undergoing
she mustn't be undergoing
we mustn't be undergoing
you mustn't be undergoing
they mustn't be undergoing	I mustn't have undergone
you mustn't have undergone
she mustn't have undergone
we mustn't have undergone
you mustn't have undergone
they mustn't have undergone	I mustn't have been undergoing
you mustn't have been undergoing
she mustn't have been undergoing
we mustn't have been undergoing
you mustn't have been undergoing
they mustn't have been undergoing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I undergo?
must you undergo?
must she undergo?
must we undergo?
must you undergo?
must they undergo? 	must I be undergoing?
must you be undergoing?
must she be undergoing?
must we be undergoing?
must you be undergoing?
must they be undergoing? 	must I have undergone?
must you have undergone?
must she have undergone?
must we have undergone?
must you have undergone?
must they have undergone? 	must I have been undergoing?
must you have been undergoing?
must she have been undergoing?
must we have been undergoing?
must you have been undergoing?
must they have been undergoing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I undergo?
mustn't you undergo?
mustn't she undergo?
mustn't we undergo?
mustn't you undergo?
mustn't they undergo? 	mustn't I be undergoing?
mustn't you be undergoing?
mustn't she be undergoing?
mustn't we be undergoing?
mustn't you be undergoing?
mustn't they be undergoing? 	mustn't I have undergone?
mustn't you have undergone?
mustn't she have undergone?
mustn't we have undergone?
mustn't you have undergone?
mustn't they have undergone? 	mustn't I have been undergoing?
mustn't you have been undergoing?
mustn't she have been undergoing?
mustn't we have been undergoing?
mustn't you have been undergoing?
mustn't they have been undergoing?