could quadruple
Verbo regular: quadruple - quadrupled- quadrupled

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could quadruple
you could quadruple
he could quadruple
we could quadruple
you could quadruple
they could quadruple 	I could be quadrupling
you could be quadrupling
he could be quadrupling
we could be quadrupling
you could be quadrupling
they could be quadrupling	I could have quadrupled
you could have quadrupled
he could have quadrupled
we could have quadrupled
you could have quadrupled
they could have quadrupled	I could have been quadrupling
you could have been quadrupling
he could have been quadrupling
we could have been quadrupling
you could have been quadrupling
they could have been quadrupling	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not quadruple
you could not quadruple
he could not quadruple
we could not quadruple
you could not quadruple
they could not quadruple 	I could not be quadrupling
you could not be quadrupling
he could not be quadrupling
we could not be quadrupling
you could not be quadrupling
they could not be quadrupling	I could not have quadrupled
you could not have quadrupled
he could not have quadrupled
we could not have quadrupled
you could not have quadrupled
they could not have quadrupled	I could not have been quadrupling
you could not have been quadrupling
he could not have been quadrupling
we could not have been quadrupling
you could not have been quadrupling
they could not have been quadrupling	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I quadruple?
could you quadruple?
could he quadruple?
could we quadruple?
could you quadruple?
could they quadruple? 	could I be quadrupling?
could you be quadrupling?
could he be quadrupling?
could we be quadrupling?
could you be quadrupling?
could they be quadrupling? 	could I have quadrupled?
could you have quadrupled?
could he have quadrupled?
could we have quadrupled?
could you have quadrupled?
could they have quadrupled? 	could I have been quadrupling?
could you have been quadrupling?
could he have been quadrupling?
could we have been quadrupling?
could you have been quadrupling?
could they have been quadrupling? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not quadruple?
could you not quadruple?
could he not quadruple?
could we not quadruple?
could you not quadruple?
could they not quadruple? 	could I not be quadrupling?
could you not be quadrupling?
could he not be quadrupling?
could we not be quadrupling?
could you not be quadrupling?
could they not be quadrupling? 	could I not have quadrupled?
could you not have quadrupled?
could he not have quadrupled?
could we not have quadrupled?
could you not have quadrupled?
could they not have quadrupled? 	could I not have been quadrupling?
could you not have been quadrupling?
could he not have been quadrupling?
could we not have been quadrupling?
could you not have been quadrupling?
could they not have been quadrupling?