Conjugación del verbo inglés
CAN STIFFEN

Verbo regular: stiffen - stiffened - stiffened

Afirmación

Forma simple	Forma con V-ing
I can stiffen you can stiffen he can stiffen we can stiffen you can stiffen they can stiffen	I can be stiffening you can be stiffening he can be stiffening we can be stiffening you can be stiffening they can be stiffening
Perfecto	Perfecto con V-ing
I can have stiffened you can have stiffened he can have stiffened we can have stiffened you can have stiffened they can have stiffened	I can have been stiffening you can have been stiffening he can have been stiffening we can have been stiffening you can have been stiffening they can have been stiffening

Negación

Forma simple	Forma con V-ing
I can't stiffen you can't stiffen he can't stiffen we can't stiffen you can't stiffen they can't stiffen	I can't be stiffening you can't be stiffening he can't be stiffening we can't be stiffening you can't be stiffening they can't be stiffening
Perfecto	Perfecto con V-ing
I can't have stiffened you can't have stiffened he can't have stiffened we can't have stiffened you can't have stiffened they can't have stiffened	I can't have been stiffening you can't have been stiffening he can't have been stiffening we can't have been stiffening you can't have been stiffening they can't have been stiffening

Forma interrogativa

Forma simple	Forma con V-ing
can I stiffen? can you stiffen? can he stiffen? can we stiffen? can you stiffen? can they stiffen?	can I be stiffening? can you be stiffening? can he be stiffening? can we be stiffening? can you be stiffening? can they be stiffening?
Perfecto	Perfecto con V-ing
can I have stiffened? can you have stiffened? can he have stiffened? can we have stiffened? can you have stiffened? can they have stiffened?	can I have been stiffening? can you have been stiffening? can he have been stiffening? can we have been stiffening? can you have been stiffening? can they have been stiffening?

Forma interro-negativa

Forma simple	Forma con V-ing
can't I stiffen? can't you stiffen? can't he stiffen? can't we stiffen? can't you stiffen? can't they stiffen?	can't I be stiffening? can't you be stiffening? can't he be stiffening? can't we be stiffening? can't you be stiffening? can't they be stiffening?
Perfecto	Perfecto con V-ing
can't I have stiffened? can't you have stiffened? can't he have stiffened? can't we have stiffened? can't you have stiffened? can't they have stiffened?	can't I have been stiffening? can't you have been stiffening? can't he have been stiffening? can't we have been stiffening? can't you have been stiffening? can't they have been stiffening?