I could checker you could checker he could checker we could checker you could checker they could checker
Forme en V-ing
I could be checkering you could be checkering he could be checkering we could be checkering you could be checkering they could be checkering
Perfect
I could have checkered you could have checkered he could have checkered we could have checkered you could have checkered they could have checkered
Perfect en V-ing
I could have been checkering you could have been checkering he could have been checkering we could have been checkering you could have been checkering they could have been checkering
Négation
Forme simple
I could not checker you could not checker he could not checker we could not checker you could not checker they could not checker
Forme en V-ing
I could not be checkering you could not be checkering he could not be checkering we could not be checkering you could not be checkering they could not be checkering
Perfect
I could not have checkered you could not have checkered he could not have checkered we could not have checkered you could not have checkered they could not have checkered
Perfect en V-ing
I could not have been checkering you could not have been checkering he could not have been checkering we could not have been checkering you could not have been checkering they could not have been checkering
Forme interrogative
Forme simple
could I checker? could you checker? could he checker? could we checker? could you checker? could they checker?
Forme en V-ing
could I be checkering? could you be checkering? could he be checkering? could we be checkering? could you be checkering? could they be checkering?
Perfect
could I have checkered? could you have checkered? could he have checkered? could we have checkered? could you have checkered? could they have checkered?
Perfect en V-ing
could I have been checkering? could you have been checkering? could he have been checkering? could we have been checkering? could you have been checkering? could they have been checkering?
Forme interro-négative
Forme simple
could I not checker? could you not checker? could he not checker? could we not checker? could you not checker? could they not checker?
Forme en V-ing
could I not be checkering? could you not be checkering? could he not be checkering? could we not be checkering? could you not be checkering? could they not be checkering?
Perfect
could I not have checkered? could you not have checkered? could he not have checkered? could we not have checkered? could you not have checkered? could they not have checkered?
Perfect en V-ing
could I not have been checkering? could you not have been checkering? could he not have been checkering? could we not have been checkering? could you not have been checkering? could they not have been checkering?