I could doubt you could doubt she could doubt we could doubt you could doubt they could doubt
Forma con V-ing
I could be doubting you could be doubting she could be doubting we could be doubting you could be doubting they could be doubting
Perfecto
I could have doubted you could have doubted she could have doubted we could have doubted you could have doubted they could have doubted
Perfecto con V-ing
I could have been doubting you could have been doubting she could have been doubting we could have been doubting you could have been doubting they could have been doubting
Negación
Forma simple
I could not doubt you could not doubt she could not doubt we could not doubt you could not doubt they could not doubt
Forma con V-ing
I could not be doubting you could not be doubting she could not be doubting we could not be doubting you could not be doubting they could not be doubting
Perfecto
I could not have doubted you could not have doubted she could not have doubted we could not have doubted you could not have doubted they could not have doubted
Perfecto con V-ing
I could not have been doubting you could not have been doubting she could not have been doubting we could not have been doubting you could not have been doubting they could not have been doubting
Forma interrogativa
Forma simple
could I doubt? could you doubt? could she doubt? could we doubt? could you doubt? could they doubt?
Forma con V-ing
could I be doubting? could you be doubting? could she be doubting? could we be doubting? could you be doubting? could they be doubting?
Perfecto
could I have doubted? could you have doubted? could she have doubted? could we have doubted? could you have doubted? could they have doubted?
Perfecto con V-ing
could I have been doubting? could you have been doubting? could she have been doubting? could we have been doubting? could you have been doubting? could they have been doubting?
Forma interro-negativa
Forma simple
could I not doubt? could you not doubt? could she not doubt? could we not doubt? could you not doubt? could they not doubt?
Forma con V-ing
could I not be doubting? could you not be doubting? could she not be doubting? could we not be doubting? could you not be doubting? could they not be doubting?
Perfecto
could I not have doubted? could you not have doubted? could she not have doubted? could we not have doubted? could you not have doubted? could they not have doubted?
Perfecto con V-ing
could I not have been doubting? could you not have been doubting? could she not have been doubting? could we not have been doubting? could you not have been doubting? could they not have been doubting?