may stiff
Regular verb: stiff - stiffed- stiffed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may stiff
you may stiff
she may stiff
we may stiff
you may stiff
they may stiff 	I may be stiffing
you may be stiffing
she may be stiffing
we may be stiffing
you may be stiffing
they may be stiffing	I may have stiffed
you may have stiffed
she may have stiffed
we may have stiffed
you may have stiffed
they may have stiffed	I may have been stiffing
you may have been stiffing
she may have been stiffing
we may have been stiffing
you may have been stiffing
they may have been stiffing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mayn't stiff
you mayn't stiff
she mayn't stiff
we mayn't stiff
you mayn't stiff
they mayn't stiff 	I mayn't be stiffing
you mayn't be stiffing
she mayn't be stiffing
we mayn't be stiffing
you mayn't be stiffing
they mayn't be stiffing	I mayn't have stiffed
you mayn't have stiffed
she mayn't have stiffed
we mayn't have stiffed
you mayn't have stiffed
they mayn't have stiffed	I mayn't have been stiffing
you mayn't have been stiffing
she mayn't have been stiffing
we mayn't have been stiffing
you mayn't have been stiffing
they mayn't have been stiffing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
may I stiff?
may you stiff?
may she stiff?
may we stiff?
may you stiff?
may they stiff? 	may I be stiffing?
may you be stiffing?
may she be stiffing?
may we be stiffing?
may you be stiffing?
may they be stiffing? 	may I have stiffed?
may you have stiffed?
may she have stiffed?
may we have stiffed?
may you have stiffed?
may they have stiffed? 	may I have been stiffing?
may you have been stiffing?
may she have been stiffing?
may we have been stiffing?
may you have been stiffing?
may they have been stiffing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mayn't I stiff?
mayn't you stiff?
mayn't she stiff?
mayn't we stiff?
mayn't you stiff?
mayn't they stiff? 	mayn't I be stiffing?
mayn't you be stiffing?
mayn't she be stiffing?
mayn't we be stiffing?
mayn't you be stiffing?
mayn't they be stiffing? 	mayn't I have stiffed?
mayn't you have stiffed?
mayn't she have stiffed?
mayn't we have stiffed?
mayn't you have stiffed?
mayn't they have stiffed? 	mayn't I have been stiffing?
mayn't you have been stiffing?
mayn't she have been stiffing?
mayn't we have been stiffing?
mayn't you have been stiffing?
mayn't they have been stiffing?