must file
Regular verb: file - filed- filed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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? 	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 	Perfect 	V-ing perfect 	
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? 	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?