could retrograde
Verbo regular: retrograde - retrograded- retrograded

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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	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	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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	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	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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? 	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? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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? 	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?