English verb conjugation
CAN RETROGRADE

Regular verb: retrograde - retrograded - retrograded

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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