I could preserve you could preserve he could preserve we could preserve you could preserve they could preserve
Forma con V-ing
I could be preserving you could be preserving he could be preserving we could be preserving you could be preserving they could be preserving
Perfecto
I could have preserved you could have preserved he 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 he could have been preserving we could have been preserving you could have been preserving they could have been preserving
Negación
Forma simple
I couldn't preserve you couldn't preserve he couldn't preserve we couldn't preserve you couldn't preserve they couldn't preserve
Forma con V-ing
I couldn't be preserving you couldn't be preserving he couldn't be preserving we couldn't be preserving you couldn't be preserving they couldn't be preserving
Perfecto
I couldn't have preserved you couldn't have preserved he couldn't have preserved we couldn't have preserved you couldn't have preserved they couldn't have preserved
Perfecto con V-ing
I couldn't have been preserving you couldn't have been preserving he couldn't have been preserving we couldn't have been preserving you couldn't have been preserving they couldn't have been preserving
Forma interrogativa
Forma simple
could I preserve? could you preserve? could he preserve? could we preserve? could you preserve? could they preserve?
Forma con V-ing
could I be preserving? could you be preserving? could he be preserving? could we be preserving? could you be preserving? could they be preserving?
Perfecto
could I have preserved? could you have preserved? could he 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 he have been preserving? could we have been preserving? could you have been preserving? could they have been preserving?
Forma interro-negativa
Forma simple
couldn't I preserve? couldn't you preserve? couldn't he preserve? couldn't we preserve? couldn't you preserve? couldn't they preserve?
Forma con V-ing
couldn't I be preserving? couldn't you be preserving? couldn't he be preserving? couldn't we be preserving? couldn't you be preserving? couldn't they be preserving?
Perfecto
couldn't I have preserved? couldn't you have preserved? couldn't he have preserved? couldn't we have preserved? couldn't you have preserved? couldn't they have preserved?
Perfecto con V-ing
couldn't I have been preserving? couldn't you have been preserving? couldn't he have been preserving? couldn't we have been preserving? couldn't you have been preserving? couldn't they have been preserving?