I must undergo you must undergo he must undergo we must undergo you must undergo they must undergo
V-ing form
I must be undergoing you must be undergoing he must be undergoing we must be undergoing you must be undergoing they must be undergoing
Perfect
I must have undergone you must have undergone he must have undergone we must have undergone you must have undergone they must have undergone
V-ing perfect
I must have been undergoing you must have been undergoing he must have been undergoing we must have been undergoing you must have been undergoing they must have been undergoing
Negation
Simple form
I must not undergo you must not undergo he must not undergo we must not undergo you must not undergo they must not undergo
V-ing form
I must not be undergoing you must not be undergoing he must not be undergoing we must not be undergoing you must not be undergoing they must not be undergoing
Perfect
I must not have undergone you must not have undergone he must not have undergone we must not have undergone you must not have undergone they must not have undergone
V-ing perfect
I must not have been undergoing you must not have been undergoing he must not have been undergoing we must not have been undergoing you must not have been undergoing they must not have been undergoing
Interrogative form
Simple form
must I undergo? must you undergo? must he undergo? must we undergo? must you undergo? must they undergo?
V-ing form
must I be undergoing? must you be undergoing? must he be undergoing? must we be undergoing? must you be undergoing? must they be undergoing?
Perfect
must I have undergone? must you have undergone? must he have undergone? must we have undergone? must you have undergone? must they have undergone?
V-ing perfect
must I have been undergoing? must you have been undergoing? must he have been undergoing? must we have been undergoing? must you have been undergoing? must they have been undergoing?
Interro-negative form
Simple form
must I not undergo? must you not undergo? must he not undergo? must we not undergo? must you not undergo? must they not undergo?
V-ing form
must I not be undergoing? must you not be undergoing? must he not be undergoing? must we not be undergoing? must you not be undergoing? must they not be undergoing?
Perfect
must I not have undergone? must you not have undergone? must he not have undergone? must we not have undergone? must you not have undergone? must they not have undergone?
V-ing perfect
must I not have been undergoing? must you not have been undergoing? must he not have been undergoing? must we not have been undergoing? must you not have been undergoing? must they not have been undergoing?