could return
Verbo regular: return - returned- returned

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could return
you could return
he could return
we could return
you could return
they could return 	I could be returning
you could be returning
he could be returning
we could be returning
you could be returning
they could be returning	I could have returned
you could have returned
he could have returned
we could have returned
you could have returned
they could have returned	I could have been returning
you could have been returning
he could have been returning
we could have been returning
you could have been returning
they could have been returning	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't return
you couldn't return
he couldn't return
we couldn't return
you couldn't return
they couldn't return 	I couldn't be returning
you couldn't be returning
he couldn't be returning
we couldn't be returning
you couldn't be returning
they couldn't be returning	I couldn't have returned
you couldn't have returned
he couldn't have returned
we couldn't have returned
you couldn't have returned
they couldn't have returned	I couldn't have been returning
you couldn't have been returning
he couldn't have been returning
we couldn't have been returning
you couldn't have been returning
they couldn't have been returning	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I return?
could you return?
could he return?
could we return?
could you return?
could they return? 	could I be returning?
could you be returning?
could he be returning?
could we be returning?
could you be returning?
could they be returning? 	could I have returned?
could you have returned?
could he have returned?
could we have returned?
could you have returned?
could they have returned? 	could I have been returning?
could you have been returning?
could he have been returning?
could we have been returning?
could you have been returning?
could they have been returning? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I return?
couldn't you return?
couldn't he return?
couldn't we return?
couldn't you return?
couldn't they return? 	couldn't I be returning?
couldn't you be returning?
couldn't he be returning?
couldn't we be returning?
couldn't you be returning?
couldn't they be returning? 	couldn't I have returned?
couldn't you have returned?
couldn't he have returned?
couldn't we have returned?
couldn't you have returned?
couldn't they have returned? 	couldn't I have been returning?
couldn't you have been returning?
couldn't he have been returning?
couldn't we have been returning?
couldn't you have been returning?
couldn't they have been returning?