should retrograde
Regular verb: retrograde - retrograded- retrograded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd retrograde
you'd retrograde
he'd retrograde
we'd retrograde
you'd retrograde
they'd retrograde 	I'd be retrograding
you'd be retrograding
he'd be retrograding
we'd be retrograding
you'd be retrograding
they'd be retrograding	I should've retrograded
you should've retrograded
he should've retrograded
we should've retrograded
you should've retrograded
they should've retrograded	I should've been retrograding
you should've been retrograding
he should've been retrograding
we should've been retrograding
you should've been retrograding
they should've been retrograding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't retrograde
you shouldn't retrograde
he shouldn't retrograde
we shouldn't retrograde
you shouldn't retrograde
they shouldn't retrograde 	I shouldn't be retrograding
you shouldn't be retrograding
he shouldn't be retrograding
we shouldn't be retrograding
you shouldn't be retrograding
they shouldn't be retrograding	I shouldn't have retrograded
you shouldn't have retrograded
he shouldn't have retrograded
we shouldn't have retrograded
you shouldn't have retrograded
they shouldn't have retrograded	I shouldn't have been retrograding
you shouldn't have been retrograding
he shouldn't have been retrograding
we shouldn't have been retrograding
you shouldn't have been retrograding
they shouldn't have been retrograding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I retrograde?
should you retrograde?
should he retrograde?
should we retrograde?
should you retrograde?
should they retrograde? 	should I be retrograding?
should you be retrograding?
should he be retrograding?
should we be retrograding?
should you be retrograding?
should they be retrograding? 	should I have retrograded?
should you have retrograded?
should he have retrograded?
should we have retrograded?
should you have retrograded?
should they have retrograded? 	should I have been retrograding?
should you have been retrograding?
should he have been retrograding?
should we have been retrograding?
should you have been retrograding?
should they have been retrograding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I retrograde?
shouldn't you retrograde?
shouldn't he retrograde?
shouldn't we retrograde?
shouldn't you retrograde?
shouldn't they retrograde? 	shouldn't I be retrograding?
shouldn't you be retrograding?
shouldn't he be retrograding?
shouldn't we be retrograding?
shouldn't you be retrograding?
shouldn't they be retrograding? 	shouldn't I have retrograded?
shouldn't you have retrograded?
shouldn't he have retrograded?
shouldn't we have retrograded?
shouldn't you have retrograded?
shouldn't they have retrograded? 	shouldn't I have been retrograding?
shouldn't you have been retrograding?
shouldn't he have been retrograding?
shouldn't we have been retrograding?
shouldn't you have been retrograding?
shouldn't they have been retrograding?