could refract
Verbo regular: refract - refracted- refracted

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could refract
you could refract
he could refract
we could refract
you could refract
they could refract 	I could be refracting
you could be refracting
he could be refracting
we could be refracting
you could be refracting
they could be refracting	I could have refracted
you could have refracted
he could have refracted
we could have refracted
you could have refracted
they could have refracted	I could have been refracting
you could have been refracting
he could have been refracting
we could have been refracting
you could have been refracting
they could have been refracting	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't refract
you couldn't refract
he couldn't refract
we couldn't refract
you couldn't refract
they couldn't refract 	I couldn't be refracting
you couldn't be refracting
he couldn't be refracting
we couldn't be refracting
you couldn't be refracting
they couldn't be refracting	I couldn't have refracted
you couldn't have refracted
he couldn't have refracted
we couldn't have refracted
you couldn't have refracted
they couldn't have refracted	I couldn't have been refracting
you couldn't have been refracting
he couldn't have been refracting
we couldn't have been refracting
you couldn't have been refracting
they couldn't have been refracting	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I refract?
could you refract?
could he refract?
could we refract?
could you refract?
could they refract? 	could I be refracting?
could you be refracting?
could he be refracting?
could we be refracting?
could you be refracting?
could they be refracting? 	could I have refracted?
could you have refracted?
could he have refracted?
could we have refracted?
could you have refracted?
could they have refracted? 	could I have been refracting?
could you have been refracting?
could he have been refracting?
could we have been refracting?
could you have been refracting?
could they have been refracting? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I refract?
couldn't you refract?
couldn't he refract?
couldn't we refract?
couldn't you refract?
couldn't they refract? 	couldn't I be refracting?
couldn't you be refracting?
couldn't he be refracting?
couldn't we be refracting?
couldn't you be refracting?
couldn't they be refracting? 	couldn't I have refracted?
couldn't you have refracted?
couldn't he have refracted?
couldn't we have refracted?
couldn't you have refracted?
couldn't they have refracted? 	couldn't I have been refracting?
couldn't you have been refracting?
couldn't he have been refracting?
couldn't we have been refracting?
couldn't you have been refracting?
couldn't they have been refracting?