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
she must stiff
we must stiff
you must stiff
they must stiff 	I must be stiffing
you must be stiffing
she must be stiffing
we must be stiffing
you must be stiffing
they must be stiffing	I must have stiffed
you must have stiffed
she 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
she 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 must not stiff
you must not stiff
she must not stiff
we must not stiff
you must not stiff
they must not stiff 	I must not be stiffing
you must not be stiffing
she must not be stiffing
we must not be stiffing
you must not be stiffing
they must not be stiffing	I must not have stiffed
you must not have stiffed
she must not have stiffed
we must not have stiffed
you must not have stiffed
they must not have stiffed	I must not have been stiffing
you must not have been stiffing
she must not have been stiffing
we must not have been stiffing
you must not have been stiffing
they must not have been stiffing	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I stiff?
must you stiff?
must she stiff?
must we stiff?
must you stiff?
must they stiff? 	must I be stiffing?
must you be stiffing?
must she be stiffing?
must we be stiffing?
must you be stiffing?
must they be stiffing? 	must I have stiffed?
must you have stiffed?
must she 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 she 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 	
must I not stiff?
must you not stiff?
must she not stiff?
must we not stiff?
must you not stiff?
must they not stiff? 	must I not be stiffing?
must you not be stiffing?
must she not be stiffing?
must we not be stiffing?
must you not be stiffing?
must they not be stiffing? 	must I not have stiffed?
must you not have stiffed?
must she not have stiffed?
must we not have stiffed?
must you not have stiffed?
must they not have stiffed? 	must I not have been stiffing?
must you not have been stiffing?
must she not have been stiffing?
must we not have been stiffing?
must you not have been stiffing?
must they not have been stiffing?