must stiff
Verbe régulier : stiff - stiffed- stiffed

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must stiff
you must stiff
he must stiff
we must stiff
you must stiff
they must stiff 	I must be stiffing
you must be stiffing
he must be stiffing
we must be stiffing
you must be stiffing
they must be stiffing	I must have stiffed
you must have stiffed
he must have stiffed
we must have stiffed
you must have stiffed
they must have stiffed	I must have been stiffing
you must have been stiffing
he must have been stiffing
we must have been stiffing
you must have been stiffing
they must have been stiffing	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't stiff
you mustn't stiff
he mustn't stiff
we mustn't stiff
you mustn't stiff
they mustn't stiff 	I mustn't be stiffing
you mustn't be stiffing
he mustn't be stiffing
we mustn't be stiffing
you mustn't be stiffing
they mustn't be stiffing	I mustn't have stiffed
you mustn't have stiffed
he mustn't have stiffed
we mustn't have stiffed
you mustn't have stiffed
they mustn't have stiffed	I mustn't have been stiffing
you mustn't have been stiffing
he mustn't have been stiffing
we mustn't have been stiffing
you mustn't have been stiffing
they mustn't have been stiffing	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I stiff?
must you stiff?
must he stiff?
must we stiff?
must you stiff?
must they stiff? 	must I be stiffing?
must you be stiffing?
must he be stiffing?
must we be stiffing?
must you be stiffing?
must they be stiffing? 	must I have stiffed?
must you have stiffed?
must he have stiffed?
must we have stiffed?
must you have stiffed?
must they have stiffed? 	must I have been stiffing?
must you have been stiffing?
must he have been stiffing?
must we have been stiffing?
must you have been stiffing?
must they have been stiffing? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I stiff?
mustn't you stiff?
mustn't he stiff?
mustn't we stiff?
mustn't you stiff?
mustn't they stiff? 	mustn't I be stiffing?
mustn't you be stiffing?
mustn't he be stiffing?
mustn't we be stiffing?
mustn't you be stiffing?
mustn't they be stiffing? 	mustn't I have stiffed?
mustn't you have stiffed?
mustn't he have stiffed?
mustn't we have stiffed?
mustn't you have stiffed?
mustn't they have stiffed? 	mustn't I have been stiffing?
mustn't you have been stiffing?
mustn't he have been stiffing?
mustn't we have been stiffing?
mustn't you have been stiffing?
mustn't they have been stiffing?