I must substantiate you must substantiate he must substantiate we must substantiate you must substantiate they must substantiate
V-ing form
I must be substantiating you must be substantiating he must be substantiating we must be substantiating you must be substantiating they must be substantiating
Perfect
I must have substantiated you must have substantiated he must have substantiated we must have substantiated you must have substantiated they must have substantiated
V-ing perfect
I must have been substantiating you must have been substantiating he must have been substantiating we must have been substantiating you must have been substantiating they must have been substantiating
Negation
Simple form
I must not substantiate you must not substantiate he must not substantiate we must not substantiate you must not substantiate they must not substantiate
V-ing form
I must not be substantiating you must not be substantiating he must not be substantiating we must not be substantiating you must not be substantiating they must not be substantiating
Perfect
I must not have substantiated you must not have substantiated he must not have substantiated we must not have substantiated you must not have substantiated they must not have substantiated
V-ing perfect
I must not have been substantiating you must not have been substantiating he must not have been substantiating we must not have been substantiating you must not have been substantiating they must not have been substantiating
Interrogative form
Simple form
must I substantiate? must you substantiate? must he substantiate? must we substantiate? must you substantiate? must they substantiate?
V-ing form
must I be substantiating? must you be substantiating? must he be substantiating? must we be substantiating? must you be substantiating? must they be substantiating?
Perfect
must I have substantiated? must you have substantiated? must he have substantiated? must we have substantiated? must you have substantiated? must they have substantiated?
V-ing perfect
must I have been substantiating? must you have been substantiating? must he have been substantiating? must we have been substantiating? must you have been substantiating? must they have been substantiating?
Interro-negative form
Simple form
must I not substantiate? must you not substantiate? must he not substantiate? must we not substantiate? must you not substantiate? must they not substantiate?
V-ing form
must I not be substantiating? must you not be substantiating? must he not be substantiating? must we not be substantiating? must you not be substantiating? must they not be substantiating?
Perfect
must I not have substantiated? must you not have substantiated? must he not have substantiated? must we not have substantiated? must you not have substantiated? must they not have substantiated?
V-ing perfect
must I not have been substantiating? must you not have been substantiating? must he not have been substantiating? must we not have been substantiating? must you not have been substantiating? must they not have been substantiating?