should stifle
Regular verb: stifle - stifled- stifled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd stifle
you'd stifle
he'd stifle
we'd stifle
you'd stifle
they'd stifle 	I'd be stifling
you'd be stifling
he'd be stifling
we'd be stifling
you'd be stifling
they'd be stifling	I should've stifled
you should've stifled
he should've stifled
we should've stifled
you should've stifled
they should've stifled	I should've been stifling
you should've been stifling
he should've been stifling
we should've been stifling
you should've been stifling
they should've been stifling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't stifle
you shouldn't stifle
he shouldn't stifle
we shouldn't stifle
you shouldn't stifle
they shouldn't stifle 	I shouldn't be stifling
you shouldn't be stifling
he shouldn't be stifling
we shouldn't be stifling
you shouldn't be stifling
they shouldn't be stifling	I shouldn't have stifled
you shouldn't have stifled
he shouldn't have stifled
we shouldn't have stifled
you shouldn't have stifled
they shouldn't have stifled	I shouldn't have been stifling
you shouldn't have been stifling
he shouldn't have been stifling
we shouldn't have been stifling
you shouldn't have been stifling
they shouldn't have been stifling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I stifle?
should you stifle?
should he stifle?
should we stifle?
should you stifle?
should they stifle? 	should I be stifling?
should you be stifling?
should he be stifling?
should we be stifling?
should you be stifling?
should they be stifling? 	should I have stifled?
should you have stifled?
should he have stifled?
should we have stifled?
should you have stifled?
should they have stifled? 	should I have been stifling?
should you have been stifling?
should he have been stifling?
should we have been stifling?
should you have been stifling?
should they have been stifling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I stifle?
shouldn't you stifle?
shouldn't he stifle?
shouldn't we stifle?
shouldn't you stifle?
shouldn't they stifle? 	shouldn't I be stifling?
shouldn't you be stifling?
shouldn't he be stifling?
shouldn't we be stifling?
shouldn't you be stifling?
shouldn't they be stifling? 	shouldn't I have stifled?
shouldn't you have stifled?
shouldn't he have stifled?
shouldn't we have stifled?
shouldn't you have stifled?
shouldn't they have stifled? 	shouldn't I have been stifling?
shouldn't you have been stifling?
shouldn't he have been stifling?
shouldn't we have been stifling?
shouldn't you have been stifling?
shouldn't they have been stifling?