I could guard you could guard he could guard we could guard you could guard they could guard
Forma con V-ing
I could be guarding you could be guarding he could be guarding we could be guarding you could be guarding they could be guarding
Perfecto
I could have guarded you could have guarded he could have guarded we could have guarded you could have guarded they could have guarded
Perfecto con V-ing
I could have been guarding you could have been guarding he could have been guarding we could have been guarding you could have been guarding they could have been guarding
Negación
Forma simple
I could not guard you could not guard he could not guard we could not guard you could not guard they could not guard
Forma con V-ing
I could not be guarding you could not be guarding he could not be guarding we could not be guarding you could not be guarding they could not be guarding
Perfecto
I could not have guarded you could not have guarded he could not have guarded we could not have guarded you could not have guarded they could not have guarded
Perfecto con V-ing
I could not have been guarding you could not have been guarding he could not have been guarding we could not have been guarding you could not have been guarding they could not have been guarding
Forma interrogativa
Forma simple
could I guard? could you guard? could he guard? could we guard? could you guard? could they guard?
Forma con V-ing
could I be guarding? could you be guarding? could he be guarding? could we be guarding? could you be guarding? could they be guarding?
Perfecto
could I have guarded? could you have guarded? could he have guarded? could we have guarded? could you have guarded? could they have guarded?
Perfecto con V-ing
could I have been guarding? could you have been guarding? could he have been guarding? could we have been guarding? could you have been guarding? could they have been guarding?
Forma interro-negativa
Forma simple
could I not guard? could you not guard? could he not guard? could we not guard? could you not guard? could they not guard?
Forma con V-ing
could I not be guarding? could you not be guarding? could he not be guarding? could we not be guarding? could you not be guarding? could they not be guarding?
Perfecto
could I not have guarded? could you not have guarded? could he not have guarded? could we not have guarded? could you not have guarded? could they not have guarded?
Perfecto con V-ing
could I not have been guarding? could you not have been guarding? could he not have been guarding? could we not have been guarding? could you not have been guarding? could they not have been guarding?