should muff
Regular verb: muff - muffed- muffed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd muff
you'd muff
she'd muff
we'd muff
you'd muff
they'd muff 	I'd be muffing
you'd be muffing
she'd be muffing
we'd be muffing
you'd be muffing
they'd be muffing	I should've muffed
you should've muffed
she should've muffed
we should've muffed
you should've muffed
they should've muffed	I should've been muffing
you should've been muffing
she should've been muffing
we should've been muffing
you should've been muffing
they should've been muffing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't muff
you shouldn't muff
she shouldn't muff
we shouldn't muff
you shouldn't muff
they shouldn't muff 	I shouldn't be muffing
you shouldn't be muffing
she shouldn't be muffing
we shouldn't be muffing
you shouldn't be muffing
they shouldn't be muffing	I shouldn't have muffed
you shouldn't have muffed
she shouldn't have muffed
we shouldn't have muffed
you shouldn't have muffed
they shouldn't have muffed	I shouldn't have been muffing
you shouldn't have been muffing
she shouldn't have been muffing
we shouldn't have been muffing
you shouldn't have been muffing
they shouldn't have been muffing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I muff?
should you muff?
should she muff?
should we muff?
should you muff?
should they muff? 	should I be muffing?
should you be muffing?
should she be muffing?
should we be muffing?
should you be muffing?
should they be muffing? 	should I have muffed?
should you have muffed?
should she have muffed?
should we have muffed?
should you have muffed?
should they have muffed? 	should I have been muffing?
should you have been muffing?
should she have been muffing?
should we have been muffing?
should you have been muffing?
should they have been muffing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I muff?
shouldn't you muff?
shouldn't she muff?
shouldn't we muff?
shouldn't you muff?
shouldn't they muff? 	shouldn't I be muffing?
shouldn't you be muffing?
shouldn't she be muffing?
shouldn't we be muffing?
shouldn't you be muffing?
shouldn't they be muffing? 	shouldn't I have muffed?
shouldn't you have muffed?
shouldn't she have muffed?
shouldn't we have muffed?
shouldn't you have muffed?
shouldn't they have muffed? 	shouldn't I have been muffing?
shouldn't you have been muffing?
shouldn't she have been muffing?
shouldn't we have been muffing?
shouldn't you have been muffing?
shouldn't they have been muffing?