could retard
Verbo regular: retard - retarded- retarded

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could retard
you could retard
he could retard
we could retard
you could retard
they could retard 	I could be retarding
you could be retarding
he could be retarding
we could be retarding
you could be retarding
they could be retarding	I could have retarded
you could have retarded
he could have retarded
we could have retarded
you could have retarded
they could have retarded	I could have been retarding
you could have been retarding
he could have been retarding
we could have been retarding
you could have been retarding
they could have been retarding	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not retard
you could not retard
he could not retard
we could not retard
you could not retard
they could not retard 	I could not be retarding
you could not be retarding
he could not be retarding
we could not be retarding
you could not be retarding
they could not be retarding	I could not have retarded
you could not have retarded
he could not have retarded
we could not have retarded
you could not have retarded
they could not have retarded	I could not have been retarding
you could not have been retarding
he could not have been retarding
we could not have been retarding
you could not have been retarding
they could not have been retarding	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I retard?
could you retard?
could he retard?
could we retard?
could you retard?
could they retard? 	could I be retarding?
could you be retarding?
could he be retarding?
could we be retarding?
could you be retarding?
could they be retarding? 	could I have retarded?
could you have retarded?
could he have retarded?
could we have retarded?
could you have retarded?
could they have retarded? 	could I have been retarding?
could you have been retarding?
could he have been retarding?
could we have been retarding?
could you have been retarding?
could they have been retarding? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not retard?
could you not retard?
could he not retard?
could we not retard?
could you not retard?
could they not retard? 	could I not be retarding?
could you not be retarding?
could he not be retarding?
could we not be retarding?
could you not be retarding?
could they not be retarding? 	could I not have retarded?
could you not have retarded?
could he not have retarded?
could we not have retarded?
could you not have retarded?
could they not have retarded? 	could I not have been retarding?
could you not have been retarding?
could he not have been retarding?
could we not have been retarding?
could you not have been retarding?
could they not have been retarding?