I could sift you could sift he could sift we could sift you could sift they could sift
Forma com V-ing
I could be sifting you could be sifting he could be sifting we could be sifting you could be sifting they could be sifting
Perfeito
I could have sifted you could have sifted he could have sifted we could have sifted you could have sifted they could have sifted
Perfeito com V-ing
I could have been sifting you could have been sifting he could have been sifting we could have been sifting you could have been sifting they could have been sifting
Negação
Forma simple
I could not sift you could not sift he could not sift we could not sift you could not sift they could not sift
Forma com V-ing
I could not be sifting you could not be sifting he could not be sifting we could not be sifting you could not be sifting they could not be sifting
Perfeito
I could not have sifted you could not have sifted he could not have sifted we could not have sifted you could not have sifted they could not have sifted
Perfeito com V-ing
I could not have been sifting you could not have been sifting he could not have been sifting we could not have been sifting you could not have been sifting they could not have been sifting
Forma interrogativa
Forma simple
could I sift? could you sift? could he sift? could we sift? could you sift? could they sift?
Forma com V-ing
could I be sifting? could you be sifting? could he be sifting? could we be sifting? could you be sifting? could they be sifting?
Perfeito
could I have sifted? could you have sifted? could he have sifted? could we have sifted? could you have sifted? could they have sifted?
Perfeito com V-ing
could I have been sifting? could you have been sifting? could he have been sifting? could we have been sifting? could you have been sifting? could they have been sifting?
Forma interro-Negação
Forma simple
could I not sift? could you not sift? could he not sift? could we not sift? could you not sift? could they not sift?
Forma com V-ing
could I not be sifting? could you not be sifting? could he not be sifting? could we not be sifting? could you not be sifting? could they not be sifting?
Perfeito
could I not have sifted? could you not have sifted? could he not have sifted? could we not have sifted? could you not have sifted? could they not have sifted?
Perfeito com V-ing
could I not have been sifting? could you not have been sifting? could he not have been sifting? could we not have been sifting? could you not have been sifting? could they not have been sifting?