English verb conjugation
MUST FILE

Regular verb: file - filed - filed

Affirmation

Simple form	V-ing form
I must file you must file he must file we must file you must file they must file	I must be filing you must be filing he must be filing we must be filing you must be filing they must be filing
Perfect	V-ing perfect
I must have filed you must have filed he must have filed we must have filed you must have filed they must have filed	I must have been filing you must have been filing he must have been filing we must have been filing you must have been filing they must have been filing

Negation

Simple form	V-ing form
I mustn't file you mustn't file he mustn't file we mustn't file you mustn't file they mustn't file	I mustn't be filing you mustn't be filing he mustn't be filing we mustn't be filing you mustn't be filing they mustn't be filing
Perfect	V-ing perfect
I mustn't have filed you mustn't have filed he mustn't have filed we mustn't have filed you mustn't have filed they mustn't have filed	I mustn't have been filing you mustn't have been filing he mustn't have been filing we mustn't have been filing you mustn't have been filing they mustn't have been filing

Interrogative form

Simple form	V-ing form
must I file? must you file? must he file? must we file? must you file? must they file?	must I be filing? must you be filing? must he be filing? must we be filing? must you be filing? must they be filing?
Perfect	V-ing perfect
must I have filed? must you have filed? must he have filed? must we have filed? must you have filed? must they have filed?	must I have been filing? must you have been filing? must he have been filing? must we have been filing? must you have been filing? must they have been filing?

Interro-negative form

Simple form	V-ing form
mustn't I file? mustn't you file? mustn't he file? mustn't we file? mustn't you file? mustn't they file?	mustn't I be filing? mustn't you be filing? mustn't he be filing? mustn't we be filing? mustn't you be filing? mustn't they be filing?
Perfect	V-ing perfect
mustn't I have filed? mustn't you have filed? mustn't he have filed? mustn't we have filed? mustn't you have filed? mustn't they have filed?	mustn't I have been filing? mustn't you have been filing? mustn't he have been filing? mustn't we have been filing? mustn't you have been filing? mustn't they have been filing?