shall stiffen
Regular verb: stiffen - stiffened- stiffened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shall stiffen
you shall stiffen
she shall stiffen
we shall stiffen
you shall stiffen
they shall stiffen 	I shall be stiffening
you shall be stiffening
she shall be stiffening
we shall be stiffening
you shall be stiffening
they shall be stiffening	I shall have stiffened
you shall have stiffened
she shall have stiffened
we shall have stiffened
you shall have stiffened
they shall have stiffened	I shall have been stiffening
you shall have been stiffening
she shall have been stiffening
we shall have been stiffening
you shall have been stiffening
they shall have been stiffening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shall not stiffen
you shall not stiffen
she shall not stiffen
we shall not stiffen
you shall not stiffen
they shall not stiffen 	I shall not be stiffening
you shall not be stiffening
she shall not be stiffening
we shall not be stiffening
you shall not be stiffening
they shall not be stiffening	I shall not have stiffened
you shall not have stiffened
she shall not have stiffened
we shall not have stiffened
you shall not have stiffened
they shall not have stiffened	I shall not have been stiffening
you shall not have been stiffening
she shall not have been stiffening
we shall not have been stiffening
you shall not have been stiffening
they shall not have been stiffening	

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

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shall I not stiffen?
shall you not stiffen?
shall she not stiffen?
shall we not stiffen?
shall you not stiffen?
shall they not stiffen? 	shall I not be stiffening?
shall you not be stiffening?
shall she not be stiffening?
shall we not be stiffening?
shall you not be stiffening?
shall they not be stiffening? 	shall I not have stiffened?
shall you not have stiffened?
shall she not have stiffened?
shall we not have stiffened?
shall you not have stiffened?
shall they not have stiffened? 	shall I not have been stiffening?
shall you not have been stiffening?
shall she not have been stiffening?
shall we not have been stiffening?
shall you not have been stiffening?
shall they not have been stiffening?