I could button you could button she could button we could button you could button they could button
Forme en V-ing
I could be buttoning you could be buttoning she could be buttoning we could be buttoning you could be buttoning they could be buttoning
Perfect
I could have buttoned you could have buttoned she could have buttoned we could have buttoned you could have buttoned they could have buttoned
Perfect en V-ing
I could have been buttoning you could have been buttoning she could have been buttoning we could have been buttoning you could have been buttoning they could have been buttoning
Négation
Forme simple
I could not button you could not button she could not button we could not button you could not button they could not button
Forme en V-ing
I could not be buttoning you could not be buttoning she could not be buttoning we could not be buttoning you could not be buttoning they could not be buttoning
Perfect
I could not have buttoned you could not have buttoned she could not have buttoned we could not have buttoned you could not have buttoned they could not have buttoned
Perfect en V-ing
I could not have been buttoning you could not have been buttoning she could not have been buttoning we could not have been buttoning you could not have been buttoning they could not have been buttoning
Forme interrogative
Forme simple
could I button? could you button? could she button? could we button? could you button? could they button?
Forme en V-ing
could I be buttoning? could you be buttoning? could she be buttoning? could we be buttoning? could you be buttoning? could they be buttoning?
Perfect
could I have buttoned? could you have buttoned? could she have buttoned? could we have buttoned? could you have buttoned? could they have buttoned?
Perfect en V-ing
could I have been buttoning? could you have been buttoning? could she have been buttoning? could we have been buttoning? could you have been buttoning? could they have been buttoning?
Forme interro-négative
Forme simple
could I not button? could you not button? could she not button? could we not button? could you not button? could they not button?
Forme en V-ing
could I not be buttoning? could you not be buttoning? could she not be buttoning? could we not be buttoning? could you not be buttoning? could they not be buttoning?
Perfect
could I not have buttoned? could you not have buttoned? could she not have buttoned? could we not have buttoned? could you not have buttoned? could they not have buttoned?
Perfect en V-ing
could I not have been buttoning? could you not have been buttoning? could she not have been buttoning? could we not have been buttoning? could you not have been buttoning? could they not have been buttoning?