could double
Verbo regular: double - doubled- doubled

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could double
you could double
he could double
we could double
you could double
they could double 	I could be doubling
you could be doubling
he could be doubling
we could be doubling
you could be doubling
they could be doubling	I could have doubled
you could have doubled
he could have doubled
we could have doubled
you could have doubled
they could have doubled	I could have been doubling
you could have been doubling
he could have been doubling
we could have been doubling
you could have been doubling
they could have been doubling	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't double
you couldn't double
he couldn't double
we couldn't double
you couldn't double
they couldn't double 	I couldn't be doubling
you couldn't be doubling
he couldn't be doubling
we couldn't be doubling
you couldn't be doubling
they couldn't be doubling	I couldn't have doubled
you couldn't have doubled
he couldn't have doubled
we couldn't have doubled
you couldn't have doubled
they couldn't have doubled	I couldn't have been doubling
you couldn't have been doubling
he couldn't have been doubling
we couldn't have been doubling
you couldn't have been doubling
they couldn't have been doubling	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I double?
could you double?
could he double?
could we double?
could you double?
could they double? 	could I be doubling?
could you be doubling?
could he be doubling?
could we be doubling?
could you be doubling?
could they be doubling? 	could I have doubled?
could you have doubled?
could he have doubled?
could we have doubled?
could you have doubled?
could they have doubled? 	could I have been doubling?
could you have been doubling?
could he have been doubling?
could we have been doubling?
could you have been doubling?
could they have been doubling? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I double?
couldn't you double?
couldn't he double?
couldn't we double?
couldn't you double?
couldn't they double? 	couldn't I be doubling?
couldn't you be doubling?
couldn't he be doubling?
couldn't we be doubling?
couldn't you be doubling?
couldn't they be doubling? 	couldn't I have doubled?
couldn't you have doubled?
couldn't he have doubled?
couldn't we have doubled?
couldn't you have doubled?
couldn't they have doubled? 	couldn't I have been doubling?
couldn't you have been doubling?
couldn't he have been doubling?
couldn't we have been doubling?
couldn't you have been doubling?
couldn't they have been doubling?