I could quiver you could quiver he could quiver we could quiver you could quiver they could quiver
Forma con V-ing
I could be quivering you could be quivering he could be quivering we could be quivering you could be quivering they could be quivering
Perfecto
I could have quivered you could have quivered he could have quivered we could have quivered you could have quivered they could have quivered
Perfecto con V-ing
I could have been quivering you could have been quivering he could have been quivering we could have been quivering you could have been quivering they could have been quivering
Negación
Forma simple
I could not quiver you could not quiver he could not quiver we could not quiver you could not quiver they could not quiver
Forma con V-ing
I could not be quivering you could not be quivering he could not be quivering we could not be quivering you could not be quivering they could not be quivering
Perfecto
I could not have quivered you could not have quivered he could not have quivered we could not have quivered you could not have quivered they could not have quivered
Perfecto con V-ing
I could not have been quivering you could not have been quivering he could not have been quivering we could not have been quivering you could not have been quivering they could not have been quivering
Forma interrogativa
Forma simple
could I quiver? could you quiver? could he quiver? could we quiver? could you quiver? could they quiver?
Forma con V-ing
could I be quivering? could you be quivering? could he be quivering? could we be quivering? could you be quivering? could they be quivering?
Perfecto
could I have quivered? could you have quivered? could he have quivered? could we have quivered? could you have quivered? could they have quivered?
Perfecto con V-ing
could I have been quivering? could you have been quivering? could he have been quivering? could we have been quivering? could you have been quivering? could they have been quivering?
Forma interro-negativa
Forma simple
could I not quiver? could you not quiver? could he not quiver? could we not quiver? could you not quiver? could they not quiver?
Forma con V-ing
could I not be quivering? could you not be quivering? could he not be quivering? could we not be quivering? could you not be quivering? could they not be quivering?
Perfecto
could I not have quivered? could you not have quivered? could he not have quivered? could we not have quivered? could you not have quivered? could they not have quivered?
Perfecto con V-ing
could I not have been quivering? could you not have been quivering? could he not have been quivering? could we not have been quivering? could you not have been quivering? could they not have been quivering?