I could preserve you could preserve she could preserve we could preserve you could preserve they could preserve
Forma con V-ing
I could be preserving you could be preserving she could be preserving we could be preserving you could be preserving they could be preserving
Perfecto
I could have preserved you could have preserved she could have preserved we could have preserved you could have preserved they could have preserved
Perfecto con V-ing
I could have been preserving you could have been preserving she could have been preserving we could have been preserving you could have been preserving they could have been preserving
Negación
Forma simple
I could not preserve you could not preserve she could not preserve we could not preserve you could not preserve they could not preserve
Forma con V-ing
I could not be preserving you could not be preserving she could not be preserving we could not be preserving you could not be preserving they could not be preserving
Perfecto
I could not have preserved you could not have preserved she could not have preserved we could not have preserved you could not have preserved they could not have preserved
Perfecto con V-ing
I could not have been preserving you could not have been preserving she could not have been preserving we could not have been preserving you could not have been preserving they could not have been preserving
Forma interrogativa
Forma simple
could I preserve? could you preserve? could she preserve? could we preserve? could you preserve? could they preserve?
Forma con V-ing
could I be preserving? could you be preserving? could she be preserving? could we be preserving? could you be preserving? could they be preserving?
Perfecto
could I have preserved? could you have preserved? could she have preserved? could we have preserved? could you have preserved? could they have preserved?
Perfecto con V-ing
could I have been preserving? could you have been preserving? could she have been preserving? could we have been preserving? could you have been preserving? could they have been preserving?
Forma interro-negativa
Forma simple
could I not preserve? could you not preserve? could she not preserve? could we not preserve? could you not preserve? could they not preserve?
Forma con V-ing
could I not be preserving? could you not be preserving? could she not be preserving? could we not be preserving? could you not be preserving? could they not be preserving?
Perfecto
could I not have preserved? could you not have preserved? could she not have preserved? could we not have preserved? could you not have preserved? could they not have preserved?
Perfecto con V-ing
could I not have been preserving? could you not have been preserving? could she not have been preserving? could we not have been preserving? could you not have been preserving? could they not have been preserving?