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 couldn't look you couldn't look he couldn't look we couldn't look you couldn't look they couldn't look
Forma com V-ing
I couldn't be looking you couldn't be looking he couldn't be looking we couldn't be looking you couldn't be looking they couldn't be looking
Perfeito
I couldn't have looked you couldn't have looked he couldn't have looked we couldn't have looked you couldn't have looked they couldn't have looked
Perfeito com V-ing
I couldn't have been looking you couldn't have been looking he couldn't have been looking we couldn't have been looking you couldn't have been looking they couldn't 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
couldn't I look? couldn't you look? couldn't he look? couldn't we look? couldn't you look? couldn't they look?
Forma com V-ing
couldn't I be looking? couldn't you be looking? couldn't he be looking? couldn't we be looking? couldn't you be looking? couldn't they be looking?
Perfeito
couldn't I have looked? couldn't you have looked? couldn't he have looked? couldn't we have looked? couldn't you have looked? couldn't they have looked?
Perfeito com V-ing
couldn't I have been looking? couldn't you have been looking? couldn't he have been looking? couldn't we have been looking? couldn't you have been looking? couldn't they have been looking?