I could button you could button he could button we could button you could button they could button
Forma com V-ing
I could be buttoning you could be buttoning he could be buttoning we could be buttoning you could be buttoning they could be buttoning
Perfeito
I could have buttoned you could have buttoned he could have buttoned we could have buttoned you could have buttoned they could have buttoned
Perfeito com V-ing
I could have been buttoning you could have been buttoning he could have been buttoning we could have been buttoning you could have been buttoning they could have been buttoning
Negação
Forma simple
I couldn't button you couldn't button he couldn't button we couldn't button you couldn't button they couldn't button
Forma com V-ing
I couldn't be buttoning you couldn't be buttoning he couldn't be buttoning we couldn't be buttoning you couldn't be buttoning they couldn't be buttoning
Perfeito
I couldn't have buttoned you couldn't have buttoned he couldn't have buttoned we couldn't have buttoned you couldn't have buttoned they couldn't have buttoned
Perfeito com V-ing
I couldn't have been buttoning you couldn't have been buttoning he couldn't have been buttoning we couldn't have been buttoning you couldn't have been buttoning they couldn't have been buttoning
Forma interrogativa
Forma simple
could I button? could you button? could he button? could we button? could you button? could they button?
Forma com V-ing
could I be buttoning? could you be buttoning? could he be buttoning? could we be buttoning? could you be buttoning? could they be buttoning?
Perfeito
could I have buttoned? could you have buttoned? could he have buttoned? could we have buttoned? could you have buttoned? could they have buttoned?
Perfeito com V-ing
could I have been buttoning? could you have been buttoning? could he have been buttoning? could we have been buttoning? could you have been buttoning? could they have been buttoning?
Forma interro-Negação
Forma simple
couldn't I button? couldn't you button? couldn't he button? couldn't we button? couldn't you button? couldn't they button?
Forma com V-ing
couldn't I be buttoning? couldn't you be buttoning? couldn't he be buttoning? couldn't we be buttoning? couldn't you be buttoning? couldn't they be buttoning?
Perfeito
couldn't I have buttoned? couldn't you have buttoned? couldn't he have buttoned? couldn't we have buttoned? couldn't you have buttoned? couldn't they have buttoned?
Perfeito com V-ing
couldn't I have been buttoning? couldn't you have been buttoning? couldn't he have been buttoning? couldn't we have been buttoning? couldn't you have been buttoning? couldn't they have been buttoning?