I could look you could look he could look we could look you could look they could look
Forma com V-ing
I could be looking you could be looking he could be looking we could be looking you could be looking they could be looking
Perfeito
I could have looked you could have looked he could have looked we could have looked you could have looked they could have looked
Perfeito com V-ing
I could have been looking you could have been looking he could have been looking we could have been looking you could have been looking they could have been looking
Negação
Forma simple
I could not look you could not look he could not look we could not look you could not look they could not look
Forma com V-ing
I could not be looking you could not be looking he could not be looking we could not be looking you could not be looking they could not be looking
Perfeito
I could not have looked you could not have looked he could not have looked we could not have looked you could not have looked they could not have looked
Perfeito com V-ing
I could not have been looking you could not have been looking he could not have been looking we could not have been looking you could not have been looking they could not have been looking
Forma interrogativa
Forma simple
could I look? could you look? could he look? could we look? could you look? could they look?
Forma com V-ing
could I be looking? could you be looking? could he be looking? could we be looking? could you be looking? could they be looking?
Perfeito
could I have looked? could you have looked? could he have looked? could we have looked? could you have looked? could they have looked?
Perfeito com V-ing
could I have been looking? could you have been looking? could he have been looking? could we have been looking? could you have been looking? could they have been looking?
Forma interro-Negação
Forma simple
could I not look? could you not look? could he not look? could we not look? could you not look? could they not look?
Forma com V-ing
could I not be looking? could you not be looking? could he not be looking? could we not be looking? could you not be looking? could they not be looking?
Perfeito
could I not have looked? could you not have looked? could he not have looked? could we not have looked? could you not have looked? could they not have looked?
Perfeito com V-ing
could I not have been looking? could you not have been looking? could he not have been looking? could we not have been looking? could you not have been looking? could they not have been looking?