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