I could confirm you could confirm he could confirm we could confirm you could confirm they could confirm
Forma con V-ing
I could be confirming you could be confirming he could be confirming we could be confirming you could be confirming they could be confirming
Perfecto
I could have confirmed you could have confirmed he could have confirmed we could have confirmed you could have confirmed they could have confirmed
Perfecto con V-ing
I could have been confirming you could have been confirming he could have been confirming we could have been confirming you could have been confirming they could have been confirming
Negación
Forma simple
I could not confirm you could not confirm he could not confirm we could not confirm you could not confirm they could not confirm
Forma con V-ing
I could not be confirming you could not be confirming he could not be confirming we could not be confirming you could not be confirming they could not be confirming
Perfecto
I could not have confirmed you could not have confirmed he could not have confirmed we could not have confirmed you could not have confirmed they could not have confirmed
Perfecto con V-ing
I could not have been confirming you could not have been confirming he could not have been confirming we could not have been confirming you could not have been confirming they could not have been confirming
Forma interrogativa
Forma simple
could I confirm? could you confirm? could he confirm? could we confirm? could you confirm? could they confirm?
Forma con V-ing
could I be confirming? could you be confirming? could he be confirming? could we be confirming? could you be confirming? could they be confirming?
Perfecto
could I have confirmed? could you have confirmed? could he have confirmed? could we have confirmed? could you have confirmed? could they have confirmed?
Perfecto con V-ing
could I have been confirming? could you have been confirming? could he have been confirming? could we have been confirming? could you have been confirming? could they have been confirming?
Forma interro-negativa
Forma simple
could I not confirm? could you not confirm? could he not confirm? could we not confirm? could you not confirm? could they not confirm?
Forma con V-ing
could I not be confirming? could you not be confirming? could he not be confirming? could we not be confirming? could you not be confirming? could they not be confirming?
Perfecto
could I not have confirmed? could you not have confirmed? could he not have confirmed? could we not have confirmed? could you not have confirmed? could they not have confirmed?
Perfecto con V-ing
could I not have been confirming? could you not have been confirming? could he not have been confirming? could we not have been confirming? could you not have been confirming? could they not have been confirming?