must staff
Regular verb: staff - staffed- staffed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must staff
you must staff
she must staff
we must staff
you must staff
they must staff 	I must be staffing
you must be staffing
she must be staffing
we must be staffing
you must be staffing
they must be staffing	I must have staffed
you must have staffed
she must have staffed
we must have staffed
you must have staffed
they must have staffed	I must have been staffing
you must have been staffing
she must have been staffing
we must have been staffing
you must have been staffing
they must have been staffing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't staff
you mustn't staff
she mustn't staff
we mustn't staff
you mustn't staff
they mustn't staff 	I mustn't be staffing
you mustn't be staffing
she mustn't be staffing
we mustn't be staffing
you mustn't be staffing
they mustn't be staffing	I mustn't have staffed
you mustn't have staffed
she mustn't have staffed
we mustn't have staffed
you mustn't have staffed
they mustn't have staffed	I mustn't have been staffing
you mustn't have been staffing
she mustn't have been staffing
we mustn't have been staffing
you mustn't have been staffing
they mustn't have been staffing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I staff?
must you staff?
must she staff?
must we staff?
must you staff?
must they staff? 	must I be staffing?
must you be staffing?
must she be staffing?
must we be staffing?
must you be staffing?
must they be staffing? 	must I have staffed?
must you have staffed?
must she have staffed?
must we have staffed?
must you have staffed?
must they have staffed? 	must I have been staffing?
must you have been staffing?
must she have been staffing?
must we have been staffing?
must you have been staffing?
must they have been staffing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I staff?
mustn't you staff?
mustn't she staff?
mustn't we staff?
mustn't you staff?
mustn't they staff? 	mustn't I be staffing?
mustn't you be staffing?
mustn't she be staffing?
mustn't we be staffing?
mustn't you be staffing?
mustn't they be staffing? 	mustn't I have staffed?
mustn't you have staffed?
mustn't she have staffed?
mustn't we have staffed?
mustn't you have staffed?
mustn't they have staffed? 	mustn't I have been staffing?
mustn't you have been staffing?
mustn't she have been staffing?
mustn't we have been staffing?
mustn't you have been staffing?
mustn't they have been staffing?