English verb conjugation
COULD RETROGRADE

Regular verb: retrograde - retrograded - retrograded

Affirmation

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

Negation

Simple form	V-ing form
I could not retrograde you could not retrograde he could not retrograde we could not retrograde you could not retrograde they could not retrograde	I could not be retrograding you could not be retrograding he could not be retrograding we could not be retrograding you could not be retrograding they could not be retrograding
Perfect	V-ing perfect
I could not have retrograded you could not have retrograded he could not have retrograded we could not have retrograded you could not have retrograded they could not have retrograded	I could not have been retrograding you could not have been retrograding he could not have been retrograding we could not have been retrograding you could not have been retrograding they could not have been retrograding

Interrogative form

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

Interro-negative form

Simple form	V-ing form
could I not retrograde? could you not retrograde? could he not retrograde? could we not retrograde? could you not retrograde? could they not retrograde?	could I not be retrograding? could you not be retrograding? could he not be retrograding? could we not be retrograding? could you not be retrograding? could they not be retrograding?
Perfect	V-ing perfect
could I not have retrograded? could you not have retrograded? could he not have retrograded? could we not have retrograded? could you not have retrograded? could they not have retrograded?	could I not have been retrograding? could you not have been retrograding? could he not have been retrograding? could we not have been retrograding? could you not have been retrograding? could they not have been retrograding?