would stiffen
Regular verb: stiffen - stiffened- stiffened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd stiffen
you'd stiffen
he'd stiffen
we'd stiffen
you'd stiffen
they'd stiffen 	I'd be stiffening
you'd be stiffening
he'd be stiffening
we'd be stiffening
you'd be stiffening
they'd be stiffening	I would've stiffened
you would've stiffened
he would've stiffened
we would've stiffened
you would've stiffened
they would've stiffened	I would've been stiffening
you would've been stiffening
he would've been stiffening
we would've been stiffening
you would've been stiffening
they would've been stiffening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I wouldn't stiffen
you wouldn't stiffen
he wouldn't stiffen
we wouldn't stiffen
you wouldn't stiffen
they wouldn't stiffen 	I wouldn't be stiffening
you wouldn't be stiffening
he wouldn't be stiffening
we wouldn't be stiffening
you wouldn't be stiffening
they wouldn't be stiffening	I wouldn't have stiffened
you wouldn't have stiffened
he wouldn't have stiffened
we wouldn't have stiffened
you wouldn't have stiffened
they wouldn't have stiffened	I wouldn't have been stiffening
you wouldn't have been stiffening
he wouldn't have been stiffening
we wouldn't have been stiffening
you wouldn't have been stiffening
they wouldn't have been stiffening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
would I stiffen?
would you stiffen?
would he stiffen?
would we stiffen?
would you stiffen?
would they stiffen? 	would I be stiffening?
would you be stiffening?
would he be stiffening?
would we be stiffening?
would you be stiffening?
would they be stiffening? 	would I have stiffened?
would you have stiffened?
would he have stiffened?
would we have stiffened?
would you have stiffened?
would they have stiffened? 	would I have been stiffening?
would you have been stiffening?
would he have been stiffening?
would we have been stiffening?
would you have been stiffening?
would they have been stiffening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
wouldn't I stiffen?
wouldn't you stiffen?
wouldn't he stiffen?
wouldn't we stiffen?
wouldn't you stiffen?
wouldn't they stiffen? 	wouldn't I be stiffening?
wouldn't you be stiffening?
wouldn't he be stiffening?
wouldn't we be stiffening?
wouldn't you be stiffening?
wouldn't they be stiffening? 	wouldn't I have stiffened?
wouldn't you have stiffened?
wouldn't he have stiffened?
wouldn't we have stiffened?
wouldn't you have stiffened?
wouldn't they have stiffened? 	wouldn't I have been stiffening?
wouldn't you have been stiffening?
wouldn't he have been stiffening?
wouldn't we have been stiffening?
wouldn't you have been stiffening?
wouldn't they have been stiffening?