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 couldn't stiff
you couldn't stiff
he couldn't stiff
we couldn't stiff
you couldn't stiff
they couldn't stiff 	I couldn't be stiffing
you couldn't be stiffing
he couldn't be stiffing
we couldn't be stiffing
you couldn't be stiffing
they couldn't be stiffing	I couldn't have stiffed
you couldn't have stiffed
he couldn't have stiffed
we couldn't have stiffed
you couldn't have stiffed
they couldn't have stiffed	I couldn't have been stiffing
you couldn't have been stiffing
he couldn't have been stiffing
we couldn't have been stiffing
you couldn't have been stiffing
they couldn't 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 	
couldn't I stiff?
couldn't you stiff?
couldn't he stiff?
couldn't we stiff?
couldn't you stiff?
couldn't they stiff? 	couldn't I be stiffing?
couldn't you be stiffing?
couldn't he be stiffing?
couldn't we be stiffing?
couldn't you be stiffing?
couldn't they be stiffing? 	couldn't I have stiffed?
couldn't you have stiffed?
couldn't he have stiffed?
couldn't we have stiffed?
couldn't you have stiffed?
couldn't they have stiffed? 	couldn't I have been stiffing?
couldn't you have been stiffing?
couldn't he have been stiffing?
couldn't we have been stiffing?
couldn't you have been stiffing?
couldn't they have been stiffing?