I must preface you must preface he must preface we must preface you must preface they must preface
V-ing form
I must be prefacing you must be prefacing he must be prefacing we must be prefacing you must be prefacing they must be prefacing
Perfect
I must have prefaced you must have prefaced he must have prefaced we must have prefaced you must have prefaced they must have prefaced
V-ing perfect
I must have been prefacing you must have been prefacing he must have been prefacing we must have been prefacing you must have been prefacing they must have been prefacing
Negation
Simple form
I must not preface you must not preface he must not preface we must not preface you must not preface they must not preface
V-ing form
I must not be prefacing you must not be prefacing he must not be prefacing we must not be prefacing you must not be prefacing they must not be prefacing
Perfect
I must not have prefaced you must not have prefaced he must not have prefaced we must not have prefaced you must not have prefaced they must not have prefaced
V-ing perfect
I must not have been prefacing you must not have been prefacing he must not have been prefacing we must not have been prefacing you must not have been prefacing they must not have been prefacing
Interrogative form
Simple form
must I preface? must you preface? must he preface? must we preface? must you preface? must they preface?
V-ing form
must I be prefacing? must you be prefacing? must he be prefacing? must we be prefacing? must you be prefacing? must they be prefacing?
Perfect
must I have prefaced? must you have prefaced? must he have prefaced? must we have prefaced? must you have prefaced? must they have prefaced?
V-ing perfect
must I have been prefacing? must you have been prefacing? must he have been prefacing? must we have been prefacing? must you have been prefacing? must they have been prefacing?
Interro-negative form
Simple form
must I not preface? must you not preface? must he not preface? must we not preface? must you not preface? must they not preface?
V-ing form
must I not be prefacing? must you not be prefacing? must he not be prefacing? must we not be prefacing? must you not be prefacing? must they not be prefacing?
Perfect
must I not have prefaced? must you not have prefaced? must he not have prefaced? must we not have prefaced? must you not have prefaced? must they not have prefaced?
V-ing perfect
must I not have been prefacing? must you not have been prefacing? must he not have been prefacing? must we not have been prefacing? must you not have been prefacing? must they not have been prefacing?