English verb conjugation
SHOULD RETROGRADE

Regular verb: retrograde - retrograded - retrograded

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?