could stiff
Verbe régulier : stiff - stiffed- stiffed

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

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I could not stiff
you could not stiff
he could not stiff
we could not stiff
you could not stiff
they could not stiff 	I could not be stiffing
you could not be stiffing
he could not be stiffing
we could not be stiffing
you could not be stiffing
they could not be stiffing	I could not have stiffed
you could not have stiffed
he could not have stiffed
we could not have stiffed
you could not have stiffed
they could not have stiffed	I could not have been stiffing
you could not have been stiffing
he could not have been stiffing
we could not have been stiffing
you could not have been stiffing
they could not have been stiffing	

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

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