must stuff
Regular verb: stuff - stuffed- stuffed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must stuff
you must stuff
she must stuff
we must stuff
you must stuff
they must stuff 	I must be stuffing
you must be stuffing
she must be stuffing
we must be stuffing
you must be stuffing
they must be stuffing	I must have stuffed
you must have stuffed
she must have stuffed
we must have stuffed
you must have stuffed
they must have stuffed	I must have been stuffing
you must have been stuffing
she must have been stuffing
we must have been stuffing
you must have been stuffing
they must have been stuffing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't stuff
you mustn't stuff
she mustn't stuff
we mustn't stuff
you mustn't stuff
they mustn't stuff 	I mustn't be stuffing
you mustn't be stuffing
she mustn't be stuffing
we mustn't be stuffing
you mustn't be stuffing
they mustn't be stuffing	I mustn't have stuffed
you mustn't have stuffed
she mustn't have stuffed
we mustn't have stuffed
you mustn't have stuffed
they mustn't have stuffed	I mustn't have been stuffing
you mustn't have been stuffing
she mustn't have been stuffing
we mustn't have been stuffing
you mustn't have been stuffing
they mustn't have been stuffing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I stuff?
must you stuff?
must she stuff?
must we stuff?
must you stuff?
must they stuff? 	must I be stuffing?
must you be stuffing?
must she be stuffing?
must we be stuffing?
must you be stuffing?
must they be stuffing? 	must I have stuffed?
must you have stuffed?
must she have stuffed?
must we have stuffed?
must you have stuffed?
must they have stuffed? 	must I have been stuffing?
must you have been stuffing?
must she have been stuffing?
must we have been stuffing?
must you have been stuffing?
must they have been stuffing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I stuff?
mustn't you stuff?
mustn't she stuff?
mustn't we stuff?
mustn't you stuff?
mustn't they stuff? 	mustn't I be stuffing?
mustn't you be stuffing?
mustn't she be stuffing?
mustn't we be stuffing?
mustn't you be stuffing?
mustn't they be stuffing? 	mustn't I have stuffed?
mustn't you have stuffed?
mustn't she have stuffed?
mustn't we have stuffed?
mustn't you have stuffed?
mustn't they have stuffed? 	mustn't I have been stuffing?
mustn't you have been stuffing?
mustn't she have been stuffing?
mustn't we have been stuffing?
mustn't you have been stuffing?
mustn't they have been stuffing?